Functions Teacher Twins©2014

Warm Up Solve each equation. 2x – 6 = 22 3 + 5x = -32 x + 29 = 14

Functions

What is a Function?

What is a Function? Each input value gives back exactly one output value. Example: Input 7 into y = 2x + 9. x = 7 y = 2(7) + 9 y = 23 Input is 7 output is 23.

Ex 1:Find the output when given the input for the function y = x – 5. Remember x is the input and y is the output. -6 -5 -4 -3

x x - 10 Ex 2: Complete the function table. y -1 -11 -1 – 10 1 0 – 10 1 2 -1 – 10 -11 0 – 10 -10 1 – 10 -9 2 – 10 -8

x x + 4 Ex 3: Complete the function table. y -2 2 -2 + 4 2 0 + 4 4 4 2 4 -2 + 4 2 0 + 4 4 2 + 4 6 4 + 4 8

Another name for the input (x value) is domain. Another name for the output (y value) is range.

Ex 4: What is the domain? What is the range? (-3, 8), (0,7), (-4,-6), (2, -5) Domain = - 4, - 3, 0, 2 Range = - 6, - 5, 7, 8

Ex 5:Find the range of the function for the given domain. y = 3x – 5 {5, 15, 22} {10, 40, 61}

Closure Find the range of the function y = 4x if the domain is {-1, 0, 1, 2}. {-4, 0, 4, 8}