Site hosted by Angelfire.com: Build your free website today!

Chapter One

The Basics




Lines:

Slope: m = rise/run = @y/@x = (Y2-Y1)/(X2-X1) Explanation: The general equation for finding the slope of a line. Point-slope: y-y1 = m(x-x1) Explanation: Used to find the slope of a line when only a point it goes through is given. Slope-intercept: y = mx + b Explanation: Gives you the slope of a line with y-intercept at b.

Functions:

Function: a rule which assigns to each element x in the domain, a single element y in the range. Domain: the domain of a function f is the set of all real numbers for which f is defined. Range: the range of a function is all of the y values that result from the input of the domain. Even functions: An even function is a function which has symmetry about the y-axis. f(-x) = f(x) Odd Functions: An odd function is a function which has symmetry about the origin. f(-x) = -f(x) Exponential functions: An exponential function is f(x) = ax, where a = a positive real number other than 1.

Rules for Exponents:

1. ax • ay = ax+y 2. ax / ay = ax-y 3. (ax)y = (ay)x = axy 4. ax • bx = (ab)x 5. (a/b)x = ax/bx Exponential Growth / Decay: Exponential growth can be described with the equation y = k • ax, when k > 1 and a >1. Exponential Decay uses the same equation, but 0 < a < 1.

Functions and Logarithms:

One-to-One function: A type of function that assigns a different element in the range to each element in the domain so that no two domain elements map to the same range element. Tested with horizontal line test.

Logarithms:

Base a logarithms are represented by the equation y = logax, which is the inverse of the base a exponential function y = ax (a>0, a --? 1). Other logarithms: logxx = ln x log10x = log x

Properties of Logarithms:

Inverse Properties: Base a: alogax = x, logaax = x, a > 1, x > 0 Base e: elnx = x, ln ex = x, x > 0 Other Properties: Product rule: logaxy = logax + logxy Quotient Rule: logax/y = logax – logay Power Rule: logaxy = y logax Change of Base Formula: logxx = ln x / ln a ***NOTE: This can be used to evaluate a base a logarithm function on your calculator.

Trigonometric Functions:

Sine: sin q = y/r Cosine: cos q = x/r Tangent: tan q = y/x Cosecant: csc q = r/y Secant: sec q = r/x Cotangent: cot q = x/y

Periodic / Period:

A function is periodic if there is a positive number h so that there is a point or points where f(x+h) = f(x). The smallest of these is the function’s period.

Transformations of Trigonometric Graphs:

Like all other functions, trigonometric functions can also be even or odd. This is a model to explain all of the transformations possible for a trigonometric function: y = a f(b(x+c)) + d a = vertical stretch or shrink; reflection about the x-axis. b = Horizontal stretch or shrink; reflection about y-axis. c = horizontal shift d = vertical shift

Inverse Trigonometric Functions:

Function Domain Range . y = sin-1x -1 x 1 0 y π y = cos-1x -1 x 1 - π /2 y π /2 y = tan-1x - < x < - π /2 < y < π /2 y = sec-1x |x| 1 0 y π , y ¹ π /2 y = csc-1x |x| 1 - π /2 y π /2, y ¹ 0 y = cot-1x - < x< 0 < y < π

***NOTE: Pictures taken from Calculus: Graphical, Numerical, Algebraic pgs 41, 41, and 47.

Back Home | Next Chapter | Reference Page