7.6 Function Operations

Objectives:

1. To add, subtract, multiply and divide functions.

2. To find the composite of two functions.

Function Operations Addition: Subtraction: Multiplication: Division:

Domains: consist of the x-values that are in the domains of both .

When finding the domain of a quotient function it does not contain an which makes

Example 1: Let . Find and their domains.

Example 2: Let . Find and their domains.

Example 3: Let . Find and their domains.

Example 4: Let . Find and their domains.

Composition Functions The composition of function with function is

written as and is defined as . The domain of consists of the values in the

domain of for which is in the domain of .

1) Evaluate 2) Use your

result as the input

for

Example 5: Let find .

Example 6: Let find .

Example 7: Let find .

Example 8:Kohl’s is having a 20% off everything in the store sale! In addition, you have a coupon for $3 off.a) Use functions to model applying the 20% discount and to model applying the

coupon.

b) Use a composition of your two functions to model how much you would pay for an item if the cashier applies the discount 1st and then the coupon.

c) Use a composition of your two functions to model how much you would pay for an item if the cashier applies the coupon 1st and then the discount.

d) How much more is any item if the clerk applies the coupon first?

Homework P 400 – 401: 1,3, 4, 5, 17,18, 23, 24, 29, 37,

41, 42, 43, 65, 67