Notes

Section 1-1 9-3-2008 Evaluate an expression: substitute for variables calculate result
 * Variable: symbol that can be replaced by a number
 * Algebraic Expression: numbers and variables combined with operations
 * Algebraic Sentence: Expressions related with a verb (less than, greater than, =, approx. less than or equal to, greater than or equal to, not equal to)

Order of Operations (PEMDAS) Parenthesis Exponents (powers) Multiplication (L to R) Division (L to R) Addition (L to R) Subtraction (L to R)

Examples: 1. Express the cost of w pencils at b cents per pencil. w * b = cost

10 pencils at 5 cents per pencil = 50 cents

2. You start with $75 in the bank. You save $25 each month. How much $ will you have after m months?

$75 + $25 = $100 $75 + $25 +$25 = 125 $75 + $25 + 25 + 25 = 150

$75 + $25m = amount of $ in bank after m months

9-4-2008 Equation: sentence stating that 2 expressions are equal. Formula: equation stating that a single variable is equal to an expression

Ex. 3 Use the formula V = 4/3(pie)r³ to find the volume of a ball that is 10 cm in diameter.

9-5-2008 What is a function? Dependent variable: value depends on other values (y, Range) Independent variable: variables on whom other variables depend on (x, Domain) Function: a pairing between two variables such that each value of the first (independent value) corresponds to exactly one value; value of the second (dependent) A relationship is a function if: and
 * Dependent variable is a function of the independent variable
 * All values of the independent must be different

(Gas Table)

Is gas a function of years? Dependent: YES Independent: NO Is years a function of gas? NO Dependent: NO Independent: YES

Domain of a function: set of values which allow subset for independent variable (x values) (y = Zx) y= dependent x= independent

Range of a function: values of dependent variables (y values)

Natural Numbers Whole Numbers Integers Rational Numbers Real Numbers

Section 1-6