Mathematics

Precalculus

The functions, algebra and trigonometry that calculus builds on, from graphs and polynomials to logarithms, vectors, conics and sequences.

  • Introductory
  • 112 lesson pairs
  • Free

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About this course

Precalculus collects the ideas that calculus takes for granted. Functions and their graphs come first, then polynomials, exponentials, logarithms and trigonometry, and then the tools for several quantities at once, like systems, vectors and matrices.

The first video lessons are out, and the rest are on the way. Every lesson already has its own page with precise definitions, a worked example for each key term and a few exercises with answers, so you can start reading now.

The reference sheet collects the main definitions and formulas unit by unit. The unit circle explorer and the function transformation explorer let you move a point or a parameter and watch the numbers and the graph respond.

The last unit looks ahead to limits, rates of change and area, and many lesson pages point to the calculus lessons where the same idea comes back.

Good to know first

  • Arithmetic with fractions and negative numbers
  • Solving linear equations
  • Basic geometry of triangles and circles

Course outline

7 of 112 lesson pairs are on YouTube so far. Each pair is a theory video followed by a practice video, numbered as parts in the video titles. Open a unit to see its lessons, or follow a lesson for its definitions and examples.

  1. Functions, Relations, and Graphs

    7 of 17 pairs on YouTube
    Open the Functions, Relations, and Graphs unit page

    Sets and Functions

    1. Theory part 1Practice part 2

      real number line, integer, fractional, and irrational examples, sets and membership, distinct elements, empty set versus the set containing zero, set-builder notation, interval notation, open and closed endpoints, unbounded intervals, compound inequalities, union, intersection, preserving order under addition and positive scaling, reversing order under negative scaling and checking solutions in the original inequality

    2. Theory part 3Practice part 4

      relation, ordered pair, function, domain, input and output, mapping diagram, independent and dependent variables, coordinate plane, vertical line test and many-to-one versus one-to-many

      Builds on Sets, Intervals, and Inequalities.

    3. Theory part 5Practice part 6

      function notation, f(x) as an output, evaluation, substitution, table and graph evaluation, arbitrary input, f(a+h) and function value versus multiplication

      Builds on Relations, Functions, and the Vertical Line Test.

    4. Theory part 7Practice part 8

      natural domain, specified domain, real-valued formula, denominator restriction, even-root restriction, odd roots, excluded values, contextual domain and preserving restrictions after cancellation

      Builds on Sets, Intervals, and Inequalities and Function Notation and Evaluation.

    5. Theory part 9Practice part 10

      codomain, image, range, range as a subset of codomain, projection of a graph, attained and unattained bounds and effect of a restricted domain

      Builds on Natural and Specified Domains and Function Notation and Evaluation.

    Rates and Graph Behavior

    1. Theory part 11Practice part 12

      linear function, slope, intercepts, point-slope form, slope-intercept form, constant rate, proportionality, units, horizontal line and vertical line is not y=f(x)

      Builds on Function Notation and Evaluation.

    2. Theory part 13Practice part 14

      intercepts, increasing and decreasing intervals, constant intervals, positive and negative values, local and global extrema, graph scale and exact versus estimated values

      Builds on Range and Codomain and Linear Functions and Constant Rate of Change.

    3. Theory part 15Practice part 16

      average rate of change, secant slope, output change divided by nonzero input change, units, signed rate and comparing intervals

      Builds on Linear Functions and Constant Rate of Change and Reading Graphs and Function Behavior.

    Special Kinds of Functions

    1. Theory part 17Practice part 18

      piecewise definition, branch domain, endpoints, open and closed graph points, evaluation, jumps and overlapping and missing branch conditions

      Builds on Sets, Intervals, and Inequalities, Function Notation and Evaluation and Reading Graphs and Function Behavior.

    2. Theory part 19Practice part 20

      absolute value as distance, piecewise definition, V-shaped graph, equations, inequalities, inside versus outside an interval, zero and negative comparison values and extraneous candidates

      Builds on Sets, Intervals, and Inequalities and Piecewise-Defined Functions.

    3. Theory part 21Practice part 22

      even function, odd function, symmetric domain, y-axis symmetry, origin symmetry, algebraic test, neither and zero function is both on a symmetric domain

      Builds on Natural and Specified Domains, Function Notation and Evaluation and Reading Graphs and Function Behavior.

    Transformations of Graphs

    1. Theory part 23Practice part 24

      parent function, rigid transformation, vertical shift, horizontal shift and reflection across axes

      Builds on Function Notation and Evaluation and Reading Graphs and Function Behavior.

    2. Theory part 25Practice part 26

      vertical stretch, horizontal compression, scale factor, dilation and multiplier

      Builds on Shifts and Reflections of Graphs.

    Combining and Inverting Functions

    1. Theory part 27Practice part 28

      sum, difference, product, quotient, domain intersection, nonzero divisor, graph of pointwise operations and restrictions survive cancellation

      Builds on Natural and Specified Domains and Function Notation and Evaluation.

    2. Theory part 29Practice part 30

      composition, inner function, outer function, ordered evaluation, noncommutativity, composite domain and decomposing a function

      Builds on Algebra of Functions.

    3. Theory part 31Practice part 32

      one-to-one, injective, distinct inputs give distinct outputs, horizontal line test and strict monotonicity as a sufficient condition

      Builds on Range and Codomain and Reading Graphs and Function Behavior.

    4. Theory part 33Practice part 34

      inverse mapping, inverse versus reciprocal, domain and range swap, reflection across y=x, solving for the inverse, restriction to an injective branch and composition identities

      Builds on Function Composition and One-to-One Functions and the Horizontal Line Test.

  2. Polynomial, Rational, and Algebraic Functions

    18 pairs coming soon
    Open the Polynomial, Rational, and Algebraic Functions unit page

    Quadratics, Circles, and Roots

    1. Theory part 35Practice part 36

      quadratic function, vertex, axis of symmetry, standard and vertex forms, factoring, completing the square, quadratic formula, discriminant, real zeros and modeling constraints

      Builds on Linear Functions and Constant Rate of Change and Shifts and Reflections of Graphs.

    2. Theory part 37Practice part 38

      distance formula, midpoint formula, circle, center, radius, standard equation, general equation and completing the square

      Builds on Quadratic Functions and Vertex Form.

    3. Theory part 39Practice part 40

      power function, integer exponent, rational exponent, principal root, even and odd roots, domain, inverse relationship and sqrt(x squared)=absolute value of x

      Builds on Natural and Specified Domains and Inverse Functions and Domain Restriction.

    4. Theory part 41Practice part 42

      original domain, least common denominator, equivalent transformations, squaring, extraneous solutions and checking candidates in the original equation

      Builds on Natural and Specified Domains, Quadratic Functions and Vertex Form and Power Functions and Root Functions.

    Polynomial Functions

    1. Theory part 43Practice part 44

      degree, even/odd degree, leading coefficient test and limits at infinity intuition

      Builds on Stretches and Compressions of Graphs and Power Functions and Root Functions.

    2. Theory part 45Practice part 46

      zero, root, x-intercept, multiplicity, sign change for odd multiplicity, no sign change for even multiplicity, local flattening and real versus nonreal roots

      Builds on Quadratic Functions and Vertex Form and End Behavior of Polynomials.

    3. Theory part 47Practice part 48

      long division, synthetic division, dividend, divisor, quotient and remainder

      Builds on Quadratic Functions and Vertex Form.

    4. Theory part 49Practice part 50

      Remainder Theorem, Factor Theorem, evaluating polynomials and extracting linear factors

      Builds on Polynomial Division.

    5. Theory part 51Practice part 52

      rational root candidates, reduced fraction p/q, factors of constant and leading coefficients, testing candidates, synthetic division and theorem gives candidates, not all roots

      Builds on Zeros and Multiplicity of Polynomials and The Remainder and Factor Theorems.

    Complex Numbers and Complete Factorization

    1. Theory part 53Practice part 54

      imaginary unit i, i squared=-1, rectangular form a+bi, real and imaginary parts, addition, multiplication, conjugate, division, complex plane, modulus and quadratic roots

      Builds on Quadratic Functions and Vertex Form and Power Functions and Root Functions.

    2. Theory part 55Practice part 56

      nonconstant complex polynomial, existence of a complex zero, degree counts roots with multiplicity, complex factorization, real coefficients and conjugate pairs and real irreducible quadratic factors

      Builds on Rational Zeros Theorem and Factoring and Complex Numbers and the Complex Plane.

    Rational Functions

    1. Theory part 57Practice part 58

      rational function, numerator, denominator, original domain, factors, cancellation, removable hole and excluded value retained in simplified expression

      Builds on Natural and Specified Domains and Polynomial Division.

    2. Theory part 59Practice part 60

      vertical asymptote, one-sided unbounded behavior, denominator zero after cancellation, removable hole, sign analysis near an excluded value and infinity is not a function value

      Builds on Zeros and Multiplicity of Polynomials and Rational Functions and Domain Restrictions.

    3. Theory part 61Practice part 62

      horizontal asymptote, dominant terms, degree comparison, separate positive and negative directions and graph may cross an asymptote

      Builds on End Behavior of Polynomials and Rational Functions and Domain Restrictions.

    4. Theory part 63Practice part 64

      polynomial division, oblique asymptote, degree difference one, remainder over divisor tends to zero and higher-degree polynomial asymptote as extension

      Builds on Polynomial Division and Horizontal Asymptotes.

    5. Theory part 65Practice part 66

      intercepts, test intervals, approaching asymptotes and crossing horizontal asymptotes

      Builds on Vertical Asymptotes and Holes, Horizontal Asymptotes and Slant (Oblique) Asymptotes.

    Polynomial and Rational Inequalities

    1. Theory part 67Practice part 68

      polynomial inequality, critical values, test points, sign chart and number line

      Builds on Sets, Intervals, and Inequalities and Zeros and Multiplicity of Polynomials.

    2. Theory part 69Practice part 70

      rational inequality, critical intervals and undefined points vs zero points

      Builds on Rational Functions and Domain Restrictions and Polynomial Inequalities.

  3. Exponential and Logarithmic Functions

    11 pairs coming soon
    Open the Exponential and Logarithmic Functions unit page

    Exponentials, e, and Logarithms

    1. Theory part 71Practice part 72

      exponential function, positive base other than one, growth factor, equal input increments, equal output ratios, growth, decay, domain, range and horizontal asymptote

      Builds on Stretches and Compressions of Graphs, Power Functions and Root Functions and Average Rate of Change and Secant Lines.

    2. Theory part 73Practice part 74

      number e, compound interest, finite compounding, continuous-compounding idea, numerical convergence, e approximately 2.71828 and approximation versus proof

      Builds on Exponential Functions and Growth/Decay.

    3. Theory part 75Practice part 76

      logarithm as exponent, positive base other than one, positive argument, inverse relationship, common logarithm, natural logarithm, domain and range

      Builds on Inverse Functions and Domain Restriction and Exponential Functions and Growth/Decay.

    4. Theory part 77Practice part 78

      log graph, exponential graph, reflections, translations and domains and ranges

      Builds on Shifts and Reflections of Graphs, Stretches and Compressions of Graphs and Logarithmic Functions as Inverses.

    Properties of Logarithms

    1. Theory part 79Practice part 80

      logarithm of a product, logarithm of a quotient, positive arguments, common base, expanding, condensing and sums do not split into logarithms

      Builds on Logarithmic Functions as Inverses.

    2. Theory part 81Practice part 82

      power law with positive argument, change of base, valid logarithm bases, exact expressions and calculator approximations

      Builds on Product and Quotient Properties of Logarithms.

    Exponential and Logarithmic Equations

    1. Theory part 83Practice part 84

      common base, isolating exponential, applying ln and exact form

      Builds on The Power Rule and Change of Base for Logarithms.

    2. Theory part 85Practice part 86

      exponential form conversion, extraneous solutions and domain validation

      Builds on The Power Rule and Change of Base for Logarithms and Solving Rational and Radical Equations.

    Models

    1. Theory part 87Practice part 88

      growth and decay model, initial value, percent rate and growth factor, discrete versus continuous rate, half-life, doubling time, compound interest, logarithmic scales and interpreting model assumptions

      Builds on The Natural Base e, Solving Exponential Equations and Solving Logarithmic Equations.

    2. Theory part 89Practice part 90

      variables and parameters, units, model assumptions, linear versus exponential growth, residual, interpolation, extrapolation, exact and approximate values and data limitations

      Builds on Average Rate of Change and Secant Lines, Reading Graphs and Function Behavior and Exponential Growth and Decay Models.

    3. Theory part 91Practice part 92

      logistic function, carrying capacity, positive parameters, early growth, saturation, symmetry about midpoint and model interpretation without differential equations

      Builds on Exponential Growth and Decay Models and Choosing and Interpreting Function Models.

  4. Trigonometric Functions

    11 pairs coming soon
    Open the Trigonometric Functions unit page

    Angles and Arcs

    1. Theory part 93Practice part 94

      standard position, degree, radian, converting units and coterminal angle

      Builds on Sets, Intervals, and Inequalities.

    2. Theory part 95Practice part 96

      arc length, sector area, angular speed and linear speed

      Builds on Angles, Radians, and Coterminal Angles.

    Triangles and the Unit Circle

    1. Theory part 97Practice part 98

      right triangle, similar triangles, opposite and adjacent sides, hypotenuse, six trigonometric ratios, angle of elevation, angle of depression and contextual units

      Builds on Quadratic Functions and Vertex Form and Angles, Radians, and Coterminal Angles.

    2. Theory part 99Practice part 100

      30-60-90, 45-45-90, exact ratios and rationalizing denominators

      Builds on Right Triangle Trigonometry.

    3. Theory part 101Practice part 102

      general angle, terminal point, radius, reference angle, quadrant signs, exact values, six trigonometric functions and excluded denominators

      Builds on Right Triangle Trigonometry and Special Right Triangles.

    4. The Unit CircleComing soon

      Theory part 103Practice part 104

      unit circle, coordinates cos theta and sin theta, radian arc length, periodicity, signed projections and exact values

      Builds on Angles, Radians, and Coterminal Angles and General Angles and Reference Angles.

    Graphs of Trigonometric Functions

    1. Theory part 105Practice part 106

      sine wave, cosine wave, periodic function, period, amplitude and midline

      Builds on The Unit Circle and Reading Graphs and Function Behavior.

    2. Theory part 107Practice part 108

      amplitude, midline, period, frequency, horizontal shift, A sin(B(x-C))+D, positive and negative parameters and fitting a sinusoidal model

      Builds on Stretches and Compressions of Graphs and Graphs of Sine and Cosine.

    3. Theory part 109Practice part 110

      tangent graph, cotangent graph, vertical asymptotes and period pi

      Builds on General Angles and Reference Angles and Graphs of Sine and Cosine.

    4. Theory part 111Practice part 112

      secant graph, cosecant graph, reciprocal functions and U-shaped branches

      Builds on General Angles and Reference Angles and Graphs of Sine and Cosine.

    Oscillation

    1. Harmonic MotionComing soon

      Theory part 113Practice part 114

      simple harmonic motion, displacement, equilibrium position, amplitude, period, phase, sinusoidal model and damping as an optional exponential-envelope example

      Builds on Amplitude, Period, and Phase Shift and Exponential Growth and Decay Models.

  5. Analytic Trigonometry and Triangles

    13 pairs coming soon
    Open the Analytic Trigonometry and Triangles unit page

    Fundamental Identities

    1. Theory part 115Practice part 116

      Pythagorean identities, reciprocal identities, quotient identities, parity identities, common domain and unit-circle derivation

      Builds on The Unit Circle, Graphs of Tangent and Cotangent and Graphs of Secant and Cosecant.

    Inverse Trigonometric Functions

    1. Theory part 117Practice part 118

      principal branch, arcsine, arccosine, domain [-1,1], restricted sine and cosine, principal output ranges and inverse versus reciprocal

      Builds on Inverse Functions and Domain Restriction and Graphs of Sine and Cosine.

    2. Theory part 119Practice part 120

      arctangent, real input and principal range, inverse cotangent, inverse secant, inverse cosecant, explicit branch conventions and reciprocal-function domains

      Builds on Inverse Functions and Domain Restriction, Graphs of Tangent and Cotangent and Graphs of Secant and Cosecant.

    3. Theory part 121Practice part 122

      composition of trigonometric and inverse functions, principal range, exact evaluation, reference triangle, absolute values and branch-dependent simplification

      Builds on Inverse Sine and Cosine Functions, Inverse Tangent and Reciprocal Trigonometric Functions and Fundamental Trigonometric Identities.

    Identities and Formulas

    1. Theory part 123Practice part 124

      identity versus equation, common domain, rewriting one side, factoring, common denominators, conjugate and numerical evidence is not proof

      Builds on Fundamental Trigonometric Identities.

    2. Theory part 125Practice part 126

      sum formula, difference formula and cofunction proof

      Builds on Fundamental Trigonometric Identities.

    3. Theory part 127Practice part 128

      double-angle, sin(2x) and cos(2x) three forms

      Builds on Sum and Difference Formulas.

    4. Theory part 129Practice part 130

      power reduction, half-angle identities, square-root sign chosen by angle and domain conditions

      Builds on Double-Angle Formulas.

    5. Theory part 131Practice part 132

      product-to-sum identities, sum-to-product identities, derivation from angle addition and oscillation and beat examples

      Builds on Sum and Difference Formulas.

    Trigonometric Equations

    1. Theory part 133Practice part 134

      isolating a trigonometric function, principal values, all solutions in an interval, general periodic solutions and excluding undefined inputs

      Builds on Inverse Sine and Cosine Functions and Inverse Tangent and Reciprocal Trigonometric Functions.

    2. Theory part 135Practice part 136

      factoring trigonometric equations, substitution by a trig expression, multiple angles, full interval for the multiple angle, extraneous candidates and domain checks

      Builds on Quadratic Functions and Vertex Form, Verifying Trigonometric Identities, Double-Angle Formulas and Solving Linear Trigonometric Equations.

    Solving Triangles

    1. Theory part 137Practice part 138

      oblique triangle, opposite side and angle, law of sines, AAS and ASA, SSA ambiguity and zero, one, or two triangles

      Builds on Right Triangle Trigonometry, General Angles and Reference Angles and Inverse Sine and Cosine Functions.

    2. Theory part 139Practice part 140

      law of cosines, SAS and SSS, included angle, triangle inequality, area one-half ab sin C, Heron formula and bearings

      Builds on Sum and Difference Formulas and The Law of Sines and the Ambiguous Case.

  6. Systems, Vectors, and Matrices

    14 pairs coming soon
    Open the Systems, Vectors, and Matrices unit page

    Systems of Equations and Inequalities

    1. Theory part 141Practice part 142

      simultaneous equations, substitution, elimination, intersections, inconsistent systems, dependent systems, unique, no, or infinitely many solutions and units

      Builds on Linear Functions and Constant Rate of Change and Quadratic Functions and Vertex Form.

    2. Theory part 143Practice part 144

      line and parabola, circle and line, substitution, elimination, intersection points, tangency, checking all equations and extraneous solutions

      Builds on Solving Rational and Radical Equations, Linear Systems in Two and Three Variables and Circles, Distance, and Midpoints.

    3. Theory part 145Practice part 146

      boundary curve, solid and dashed boundary, test point, half-plane, feasible region, intersection, union and linear and nonlinear inequalities

      Builds on Sets, Intervals, and Inequalities, Rational Inequalities, Reading Graphs and Function Behavior and Nonlinear Systems and Curve Intersections.

    Partial Fractions

    1. Theory part 147Practice part 148

      proper rational function, polynomial division first, distinct linear factors, repeated linear factors, coefficient matching, solving a linear system and original-domain equality

      Builds on Polynomial Division, Rational Functions and Domain Restrictions and Linear Systems in Two and Three Variables.

    2. Theory part 149Practice part 150

      irreducible real quadratic factor, linear numerator, repeated powers, coefficient matching, proper rational function and real factorization

      Builds on The Fundamental Theorem of Algebra and Partial Fraction Decomposition (Linear Factors).

    Vectors

    1. Theory part 151Practice part 152

      vector, magnitude, direction, directed line segment and parallelogram law

      Builds on Right Triangle Trigonometry and General Angles and Reference Angles.

    2. Theory part 153Practice part 154

      component form, standard unit vectors and scalar multiplication

      Builds on Linear Functions and Constant Rate of Change and Geometric Vectors and Vector Addition.

    3. Theory part 155Practice part 156

      dot product, angle between nonzero vectors, orthogonality, component formula, geometric formula, zero-vector caveat and parallel vectors

      Builds on Algebraic Vectors and Component Form and The Law of Cosines and Triangle Area.

    4. Theory part 157Practice part 158

      scalar component, vector projection onto a nonzero vector, orthogonal decomposition, constant-force work, units and sign of work

      Builds on The Dot Product and Orthogonality.

    Matrices

    1. Theory part 159Practice part 160

      matrix, dimensions, scalar multiplication and matrix addition

      Builds on Linear Systems in Two and Three Variables.

    2. Theory part 161Practice part 162

      compatible dimensions, row-column dot product, composition of linear maps, noncommutativity, identity matrix and zero matrix

      Builds on The Dot Product and Orthogonality and Introduction to Matrices and Matrix Addition.

    3. Theory part 163Practice part 164

      augmented matrix, elementary row operations, row echelon form, reduced row echelon form, pivots, free variables, back-substitution and inconsistent row

      Builds on Introduction to Matrices and Matrix Addition and Linear Systems in Two and Three Variables.

    4. Theory part 165Practice part 166

      2 by 2 and 3 by 3 determinants, signed area and volume scaling, orientation, expansion by minors, zero determinant, singularity and Cramer rule as an optional method

      Builds on Matrix Multiplication and Gaussian Elimination and Solution Structure.

    5. Theory part 167Practice part 168

      inverse matrix, identity, square and nonsingular conditions, 2 by 2 inverse formula, matrix equation, solving a system and inverse versus entrywise reciprocal

      Builds on Determinants and Their Geometric Meaning.

  7. Complex Polar Form and Polar Coordinates

    7 pairs coming soon
    Open the Complex Polar Form and Polar Coordinates unit page

    Polar Coordinates

    1. Theory part 169Practice part 170

      pole, polar axis, radius, angle, negative radius, nonunique coordinates, origin and plotting points

      Builds on Angles, Radians, and Coterminal Angles and The Unit Circle.

    2. Theory part 171Practice part 172

      x=r cos theta, y=r sin theta, r squared=x squared+y squared, atan2 and quadrant choice, point conversion, equation conversion and domain and tracing checks

      Builds on Quadratic Functions and Vertex Form and Introduction to Polar Coordinates.

    Complex Numbers in Polar Form

    1. Theory part 173Practice part 174

      modulus, argument, polar representation, cis notation, nonunique arguments, principal argument convention, zero has no unique argument and rectangular conversion

      Builds on Complex Numbers and the Complex Plane and Converting Between Polar and Rectangular Coordinates.

    2. Theory part 175Practice part 176

      complex multiplication, complex division by a nonzero number, modulus multiplication and division, argument addition and subtraction and rotation and scaling

      Builds on Sum and Difference Formulas and Polar Form of Complex Numbers.

    3. Theory part 177Practice part 178

      De Moivre theorem for integer powers, nth roots of nonzero complex numbers, n distinct roots, roots of unity, regular polygons and angular spacing

      Builds on Products and Quotients in Polar Form.

    Polar Graphs

    1. Theory part 179Practice part 180

      symmetry tests, limacon, cardioid and maximum r

      Builds on Amplitude, Period, and Phase Shift and Converting Between Polar and Rectangular Coordinates.

    2. Theory part 181Practice part 182

      rose curves, integer angular frequency, odd/even petal counts under stated form, lemniscates, negative radius, valid real branches and tracing interval

      Builds on Power-Reducing and Half-Angle Formulas and Polar Graphs of Limacons and Cardioids.

  8. Conics, Parametric Equations, and Space

    9 pairs coming soon
    Open the Conics, Parametric Equations, and Space unit page

    Conic Sections

    1. Theory part 183Practice part 184

      conic section, parabola, focus, directrix, vertex and latus rectum

      Builds on Circles, Distance, and Midpoints.

    2. Theory part 185Practice part 186

      ellipse as constant sum of distances, foci, semimajor and semiminor axes, center, c squared=a squared-b squared, eccentricity and circle as special case

      Builds on Circles, Distance, and Midpoints.

    3. Theory part 187Practice part 188

      hyperbola as constant absolute difference of distances, foci, transverse and conjugate axes, vertices, asymptotes, c squared=a squared+b squared and eccentricity

      Builds on Circles, Distance, and Midpoints and Slant (Oblique) Asymptotes.

    4. Theory part 189Practice part 190

      translated conics, completing the square and shifting vertices

      Builds on Parabolas as Geometric Loci, Ellipses as Geometric Loci and Hyperbolas as Geometric Loci.

    5. Rotation of AxesComing soon

      Theory part 191Practice part 192

      rotated coordinates, mixed xy term, angle convention, classification by discriminant with degeneracy caveats and geometric rotation

      Builds on Sum and Difference Formulas and Shifted Conics and Completing the Square.

    6. Theory part 193Practice part 194

      focus at the pole, eccentricity e and directrix distance d

      Builds on Converting Between Polar and Rectangular Coordinates, Parabolas as Geometric Loci, Ellipses as Geometric Loci and Hyperbolas as Geometric Loci.

    Parametric Equations

    1. Theory part 195Practice part 196

      parameter, paired coordinate functions, parameter interval, orientation, tracing speed and same curve with different parameterizations

      Builds on Function Notation and Evaluation and The Unit Circle.

    2. Theory part 197Practice part 198

      elimination by substitution or identity, rectangular equation, inherited restrictions, orientation information lost and extraneous branches

      Builds on Fundamental Trigonometric Identities and Parametric Equations and Oriented Paths.

    Three Dimensions

    1. Theory part 199Practice part 200

      3D space, octants, distance formula in 3D and spheres

      Builds on Circles, Distance, and Midpoints and Algebraic Vectors and Component Form.

  9. Sequences, Series, and Induction

    8 pairs coming soon
    Open the Sequences, Series, and Induction unit page

    Sequences

    1. Theory part 201Practice part 202

      sequence as a function of an integer index, indexing convention, explicit term, finite and infinite sequences, factorial and arithmetic on terms

      Builds on Function Notation and Evaluation and Power Functions and Root Functions.

    2. Theory part 203Practice part 204

      initial value, recursive rule, Fibonacci recurrence, generating terms, explicit versus recursive description and recursion alone does not guarantee convergence

      Builds on Introduction to Sequences and Factorials.

    Series

    1. Theory part 205Practice part 206

      summation index, summand, lower and upper bounds, dummy index, finite sum, partial sum, sum rules, reindexing and sequence versus series

      Builds on Introduction to Sequences and Factorials.

    2. Theory part 207Practice part 208

      common difference, explicit nth term, arithmetic partial sums, endpoint averaging, pairing argument and indexing

      Builds on Linear Functions and Constant Rate of Change and Sigma Notation and Partial Sums.

    3. Theory part 209Practice part 210

      common ratio, explicit nth term, finite geometric sum, r=1 exception, derivation by subtraction and applications

      Builds on Exponential Functions and Growth/Decay and Sigma Notation and Partial Sums.

    4. Theory part 211Practice part 212

      partial sums, convergence, divergence, absolute value of ratio less than one, infinite geometric sum, r=1 and r=-1 and repeating decimals

      Builds on Geometric Sequences and Series.

    Induction and the Binomial Theorem

    1. Theory part 213Practice part 214

      statement indexed by integers, base case, inductive hypothesis, inductive step, starting index and proof versus checking examples

      Builds on Introduction to Sequences and Factorials and Sigma Notation and Partial Sums.

    2. Theory part 215Practice part 216

      nonnegative integer exponent, binomial theorem, Pascal triangle, binomial coefficient, factorial formula, combinations and finite expansion versus infinite binomial series

      Builds on Introduction to Sequences and Factorials and Sigma Notation and Partial Sums.

  10. The Bridge to Calculus

    4 pairs coming soon
    Open the The Bridge to Calculus unit page

    Limits

    1. Theory part 217Practice part 218

      sequence limit intuition, convergence, divergence, oscillation, bounded does not imply convergent, geometric examples and numerical evidence versus proof

      Builds on Recursive Sequences and the Fibonacci Sequence and Infinite Geometric Series and Convergence.

    2. Theory part 219Practice part 220

      nearby inputs, function value versus limiting value, left and right approach, numerical tables, graph window, nonexistence and evidence versus proof

      Builds on Piecewise-Defined Functions, Vertical Asymptotes and Holes, Horizontal Asymptotes and Sequence Behavior and Limiting Values.

    Rates and Areas

    1. Theory part 221Practice part 222

      difference quotient, h nonzero, original domain, algebraic simplification, shrinking secants, instantaneous-rate limit when it exists and corners and failure of a single tangent slope

      Builds on Average Rate of Change and Secant Lines and Approaching a Limit Numerically and Graphically.

    2. Theory part 223Practice part 224

      nonnegative function, finite partition, left and right rectangles, lower and upper estimates under stated monotonicity, refinement, area intuition and finite sum versus limiting area

      Builds on Sigma Notation and Partial Sums and Approaching a Limit Numerically and Graphically.