Calc Medic - Calculus Quick Notes

Unit 1: Exploring Rates of Change

  • Functions and Function Notation

    • Functions are crucial for modeling relationships between variables, a key skill assessed on the AP exam.

    • Understanding domain and range is essential for contextual problems.

    • Function notation is used extensively; be prepared to interpret and manipulate functions.

  • Graphs of Functions

    • Visual analysis of graphs to determine increasing, decreasing intervals, and key points is fundamental.

    • Connect graph behavior to real-world scenarios.

  • Concavity

    • Understand how the sign of a graph's slope indicates increasing or decreasing behavior.

    • Concavity relates directly to the rate of change; interpret its meaning in context.

      • Concave up: Rate of change is increasing, often related to acceleration.

      • Concave down: Rate of change is decreasing, often related to deceleration.

  • Rates of Change

    • Calculate and interpret the average rate of change over an interval; this is a common AP question.

    • Average Rate of Change = \frac{\Delta y}{\Delta x} = \frac{f(x2) - f(x1)}{x2 - x1}

    • Estimate and interpret instantaneous rates of change.

    • Compare rates of change across different intervals.

Change in Functions

  • Linear Functions

    • Recognize that linear functions have a constant rate of change.

    • Interpret slope as a rate of change in applied problems.

    • f(x) = mx + b, where m is the constant rate of change (slope).

  • Quadratic Functions

    • Know that for quadratic functions, the change in output values over equal intervals grows linearly.

    • Understand the relationship between the concavity of a parabola and increasing/decreasing average rates of change.

    • f(x) = ax^2 + bx + c, where the average rates of change vary linearly.

Unit 2: Polynomial and Rational Functions

  • Polynomial Functions and Rates of Change

    • Be familiar with the key characteristics of polynomial functions:

      • Degree

      • Leading coefficient

      • Relative and absolute extrema (maxima and minima)

      • Points of inflection (where concavity changes)

    • The degree of a polynomial can be determined using finite differences.

  • Zeros of Polynomial Functions

    • Understand how a root's multiplicity affects the graph at an x-intercept:

      • Even multiplicity: The graph touches the x-axis but does not cross.

      • Odd multiplicity: The graph crosses the x-axis.

    • A polynomial of degree n has exactly n complex zeros and can be written as a product of n linear factors.

    • P(x) = a(x - r1)(x - r2)…(x - rn), where ri are the zeros.

    • Find all zeros of a polynomial function when given in factored form.

    • Imaginary zeros occur when the polynomial's graph does not intersect the x-axis; these are important for complete analysis.

  • Even and Odd Polynomials

    • Even functions: Symmetrical about the y-axis; f(-x) = f(x).

    • Odd functions: Symmetrical about the origin; f(-x) = -f(x).

    • Algebraically prove whether polynomial functions are even, odd, or neither.

  • Polynomial Functions and End Behavior

    • Determine the end behavior of a polynomial based on its degree and leading coefficient:

      • Even degree, positive leading coefficient: Both ends go up.

      • Even degree, negative leading coefficient: Both ends go down.

      • Odd degree, positive leading coefficient: Left end goes down, right end goes up.

      • Odd degree, negative leading coefficient: Left end goes up, right end goes down.

    • The end behavior is determined by its leading term.

    • Use limit notation to describe the end behavior:

      • \lim
        x \to \infty} P(x) = \pm \infty

      • \lim
        x \to -\infty} P(x) = \pm \infty

  • Rational Functions and End Behavior

    • Interpret the behavior of a rational function within a given context, focusing on horizontal asymptotes.

    • Determine end behavior by comparing the degrees of the numerator and denominator:

      • Degree of numerator < degree of denominator: Horizontal asymptote at y = 0.

      • Degree of numerator = degree of denominator: Horizontal asymptote at y = \frac{leading coefficient of numerator}{leading coefficient of denominator}.

      • Degree of numerator > degree of denominator: No horizontal asymptote (may have a slant asymptote).

    • The end behavior is determined by the quotient of leading terms.

  • Graphs of Rational Functions

    • Key features of a rational function for AP exam success:

      • Domain

      • Intercepts

      • Holes

      • Vertical asymptotes

    • Identify these features from both the graph and the equation in factored form.

    • Use one-sided limit notation to describe behavior near vertical asymptotes:

      • \lim
        x \to a^-} R(x) = \pm \infty

      • \lim
        x \to a^+} R(x) = \pm \infty

    • Determine the y-value of a hole by examining function outputs close to the x-value of the hole.

  • Factored and Standard Forms of Polynomials

    • Advantages of factored form: Easy to identify zeros.

    • Advantages of standard form: Easy to evaluate for specific values of x.

    • Convert polynomials from factored to standard forms and vice versa fluently.

    • When (x - k) is a factor, x = k is a zero.

    • Find all zeros of a polynomial function by hand or using technology.

  • Equivalent Representations of Rational Functions

    • Extend concepts of factors, dividends, divisors, quotients, and remainders to functions.

    • Divide polynomials using an area model.

    • Rewrite a rational function to reveal different characteristics, including slant asymptotes.

  • The Binomial Theorem

    • Generalize patterns for the expansion of binomials and connect to Pascal's triangle.

    • Expand binomial expressions using the Binomial Theorem:

    • (a + b)^n = \sum
      k=0}^{n} {n \choose k} a^{n-k} b^k where {n \choose k} = \frac{n!}{k!(n-k)!}

Unit 3: Constructing Functions

  • A Library of Parent Functions

    • Understand parent functions as the most basic in a function family.

    • Key features of six parent functions:

      • Identity: f(x) = x

      • Absolute value: f(x) = |x|

      • Square root: f(x) = \sqrt{x}

      • Quadratic: f(x) = x^2

      • Cubic: f(x) = x^3

      • Reciprocal: f(x) = \frac{1}{x}

    • Analyze and compare the key features of parent functions.

  • Transformations of Functions

    • Construct a new function by applying translations, dilations, and reflections to a parent function.

    • Describe transformations from an equation or graph.

    • Determine the domain and range of a transformed function.

  • Piecewise Functions

    • Interpret and evaluate functions that have different rules for certain domain intervals.

    • Graph piecewise-defined functions.

    • Write equations for piecewise-defined functions from a graph or context.

  • Selecting a Function Model

    • Identify the appropriate function type based on observations about how quantities are changing.

    • Describe assumptions and restrictions related to a particular function model.

  • Constructing a Function Model

    • Construct a function model based on mathematical or contextual constraints.

    • Construct a function model using transformations from a parent function.

    • Use rational functions to model inversely proportional quantities.

    • Apply a function model to answer questions about a data set or scenario.

Unit 4: Exponential Functions

  • Change in Arithmetic Sequences

    • Sequences are functions with a domain of positive integers.

    • Write an explicit rule for arithmetic sequences using the common difference:

    • an = a1 + (n - 1)d, where d is the common difference.

    • Apply understanding of arithmetic sequences to determine the common difference and find missing terms.

  • Change in Geometric Sequences

    • Write an explicit rule for geometric sequences using the common ratio:

    • an = a1 * r^(n-1), where r is the common ratio.

    • Apply understanding of geometric sequences and exponents/roots to determine the common ratio and find missing terms.

    • Compare arithmetic and geometric sequences.

  • Change in Linear and Exponential Functions

    • Create linear and exponential functions using constant rates of change and constant proportions:

      • Linear: f(x) = mx + b, constant rate of change m.

      • Exponential: f(x) = a * b^x, constant proportion b.

    • Interpret the parameters of linear and exponential functions in context and describe growth patterns.

    • Describe similarities and differences between linear and exponential functions.

  • Exponential Functions

    • Recognize exponential growth or decay scenarios by identifying a fixed percent change or common ratio.

    • Write equations of the form y = ab^x to model growth or decay scenarios.

  • Graphing and Manipulating Exponential Functions

    • Graph functions of the form y = ab^x and identify key characteristics, including end behavior, concavity, domain/range, asymptotes, and intercepts.

    • Determine the growth factor from the graph of an exponential function, including transformed functions.

    • Apply knowledge of transformations to exponential functions.

    • Explain why two exponential functions are equivalent using exponent properties and transformations.

  • Modeling with the Natural Base, “e”

    • Describe the effects of compounding interest and derive the compound interest formula.

    • A = P(1 + \frac{r}{n})^{nt}, where A is the final amount, P is the principal, r is the interest rate, n is the number of times interest is compounded per year, and t is the time in years.

    • Continuously compounded interest: A = Pe^{rt}.

    • Use an exponential model to make predictions about the dependent variable.

    • Understand "e" as the base rate of growth for all continually growing processes.

  • Constructing Exponential Models

    • Construct exponential models from an initial value and ratio or from two input-output pairs.

    • Use an exponential model to make predictions about the dependent variable.

    • Understand how equivalent forms of an exponential function can reveal different properties about its growth rate.

  • Using Regression Models

    • Use data set characteristics to decide whether a linear, quadratic, or exponential model is most appropriate.

    • Create a regression model for a scenario using technology.

    • Use a residual plot to validate whether a given model was appropriate.

Unit 5: Logarithmic Functions

  • Compositions of Functions

    • When two functions are composed, the output of one becomes the input of the second.

    • Write equations for compositions of functions:

    • (f \circ g)(x) = f(g(x))

    • Decompose a complicated function into a composite of two or more functions.

    • Reason about the domain of a composition of functions.

  • Intro to Inverse Functions

    • Solve equations of the form f(x) = c to recognize the need for a function that "undoes" the original function.

    • Understand the relationship between inputs and outputs of a function and its inverse; use this to evaluate inverse functions.

    • Find an inverse function algebraically.

    • Verify that one function is the inverse of another by composition:

    • f(f^{-1}(x)) = x and f^{-1}(f(x)) = x

  • Graphs of Inverse Functions

    • Understand why a function must be one-to-one (invertible) for the inverse mapping to be a function.

    • Explore relationships between the graph of a function and its inverse, including their domains and ranges.

    • The graph of the inverse function is a reflection of the original function across the line y = x.

  • Inverses of Exponential Functions

    • Understand that a logarithm represents the exponent to which the base must be raised to attain the input value; use this to evaluate logarithmic expressions.

    • y = log_b(x) is equivalent to b^y = x

    • Use exponential and logarithmic forms to write equivalent statements about powers.

    • Understand the inverse relationship between how inputs and outputs change in exponential versus logarithmic functions.

    • Understand the inverse relationship between exponential and logarithmic functions of the same base, including the natural base, e.

  • Graphs of Logarithmic Functions

    • Describe key features (domain, range, asymptotes, concavity, and end behavior) of the graph of a parent logarithmic function, y = log_b x.

    • Sketch parent logarithmic functions and their transformations.

    • Connect key features on the graphs of exponential and logarithmic functions.

  • Logarithm Properties

    • Discover and use the sum, difference, and power properties of logarithms to rewrite logarithmic expressions.

    • logb(mn) = logb(m) + log_b(n)

    • logb(\frac{m}{n}) = logb(m) - log_b(n)

    • log*b(m^p) = p * log*b(m)

    • Explain why two logarithmic functions are equivalent using logarithm properties and transformations.

  • Solving Exponential and Logarithmic Equations

    • Solve exponential and logarithmic equations by rewriting them in equivalent forms using properties.

    • Identify and exclude extraneous solutions.

    • Write equations for inverse functions by applying inverse operations.

  • Modeling with Logarithmic Functions

    • Understand that a logarithmic model takes quantities that grow proportionally and assigns them output values that grow linearly.

    • Identify situations that could be modeled with a logarithmic function.

    • Construct logarithmic models using input-output pairs or transformations.

    • Use logarithmic function models to predict values of the dependent variable.

  • Semi-log Plots

    • Linearize quantities exhibiting exponential growth or decay using a log transformation.

    • Interpret the parameters of exponential regression models and their associated linear regression models after a log transformation.

Unit 6: Exploring Sine and Cosine Functions

  • Periodic Phenomena

    • Identify periodic relationships between variables and construct their graphs.

    • Describe key features of a periodic function:

      • Period

      • Amplitude

      • Midline.

  • Angles on the Coordinate Plane

    • Understand how to measure angles in standard position and their properties.

    • Understand that a radian is an angle measure with an arc length of one radius.

    • 2\pi radians = 360 degrees.

    • Label the angles on the unit circle in radians using proportional reasoning.

  • Defining Sine, Cosine, and Tangent for Any Angle

    • Extend the definition of sine, cosine, and tangent ratios to angles greater than 90° using the coordinate plane.

    • Understand why in a unit circle, sine and cosine ratios correspond with the y-value and x-value, respectively:

      • sin(\theta) = y

      • cos(\theta) = x

    • Understand that in a unit circle, the tangent of an angle is the ratio of the y-coordinate to the x-coordinate:

    • tan(\theta) = \frac{y}{x} = \frac{sin(\theta)}{cos(\theta)}

    • Use symmetry to identify relationships between the sine, cosine, and tangent values of angles in all four quadrants.

  • Coordinates on the Unit Circle

    • Use special right triangles to determine the coordinates at key points on the unit circle.

    • 30-60-90 triangle and 45-45-90 triangle.

    • Evaluate sine, cosine, and tangent for key angles on the unit circle.

    • Find coordinates of points on circles where r \neq 1.

  • Graphs of Sine and Cosine

    • Construct graphs of the sine and cosine functions using values from the unit circle.

    • Identify key characteristics for the parent functions y = sin x and y = cos x, including domain, amplitude, midline, period, and symmetry.

  • Transformations of Sine and Cosine

    • Determine how the amplitude, period, domain, range, and midline of sinusoidal functions are affected by transformations:

    • y = A sin(B(x - C)) + D

      • Amplitude: |A|

      • Period: \frac{2\pi}{|B|}

      • Phase shift: C

      • Vertical shift: D

    • Graph transformed sine and cosine functions given an equation.

  • Modeling with Trigonometric Functions

    • Interpret a sinusoidal function's period, amplitude, midline, and range in context.

    • Construct a trigonometric model based on data points and key features.

Unit 7: Working with Trigonometric Functions

  • The Tangent Function

    • Understand that the tangent of an angle is determined by the slope of the terminal ray and use this to understand the behavior of the tangent function.

    • Describe key features of the graph of the tangent function, including its domain, range, x-intercepts, and period.

    • Identify how the graph of the parent tangent function is affected by transformations.

  • Inverse Trig Functions

    • Understand that inverse trigonometric functions input ratios and output angles.

    • Explain why and how the domains of sine, cosine, and tangent must be restricted to create an inverse function.

    • Evaluate inverse trig expressions.

  • Trigonometric Equations and Inequalities

    • Extend the process of inverse operations to trigonometric equations and inequalities.

    • Understand that using the unit circle gives infinite solutions while inverse trig functions give only one solution; expand using symmetry.

  • The Secant, Cosecant, and Cotangent Functions

    • Define the secant, cosecant, and cotangent functions as the reciprocal of the cosine, sine, and tangent functions, respectively:

      • sec(\theta) = \frac{1}{cos(\theta)}

      • csc(\theta) = \frac{1}{sin(\theta)}

      • cot(\theta) = \frac{1}{tan(\theta)}

    • Understand how the zeros, vertical asymptotes, and range are related for a trigonometric function and its reciprocal function.

  • Trigonometric Relationships

    • Explore relationships between all six trigonometric functions, including the Pythagorean identities:

      • sin^2(\theta) + cos^2(\theta) = 1

      • 1 + tan^2(\theta) = sec^2(\theta)

      • 1 + cot^2(\theta) = csc^2(\theta)

    • Use identities to establish and verify other trigonometric relationships and solve trigonometric equations.

  • Angle Sum Identities

    • Find exact values for the sine and cosine of angles not on the unit circle by writing the angle as a sum or difference of known angles:

      • sin(a + b) = sin(a)cos(b) + cos(a)sin(b)

      • $$cos(a + b) = cos(a)cos(