2.1 Review of Functions Learning Objective: to remember what a function is and what to do with it. Warm-up (IN) 1.Write down everything you think of when you hear the word “function.”

Notes! Relation – A set of ordered pairs Domain – the set of all input, or x, values Range – the set of all output, or y, values Function – A relation in which each value of the domain is paired with exactly one value of the range Ex 1 – Is the relation a function? yes no yes no

Vertical Line Test – Used to determine if a graph is a function. If a vertical line hits the graph no more than one time, then it’s a function Ex 2 – Is the graph a function? a. b. yes no

Ex 3 –

Ex 4 – Find the domain Can’t divide by zero! Can’t take square root of a negative! Switch inequality when you mult or div by a neg.

In addition to evaluating functions at specific #s (f(2)), it is important to be able to evaluate functions at expressions that involve 1 or more variables. the difference quotient is studied extensively in calculus

Ex 5 – Replace x with a Replace a with a+h

HW – pg , #2-48 even, 74, 76, 81 Out – Summary – I’m glad I remember _______ or I wish I remembered ______ about functions. Don’t forget about POW!!