A27­6Notes.notebook
March 29, 2016
Algebra 2
Ch.7 Notes Page 44
P44 7­6 Function Operations (Review)
Aug 19­6:20 AM
Operations with Functions
f(x) = 3x + 8
g(x) = 2x ­ 12
Domains are the x­values that are the domains of both functions.
Addition (f + g)(x) = f(x) + g(x)
Subtraction (f ­ g)(x) = f(x) ­ g(x)
Nov 8­8:59 AM
1
A27­6Notes.notebook
March 29, 2016
Operations with Functions
Domains are the x­values f(x) = x2 ­ 1
that are the domains of g(x) = x + 1
both functions.
Multiplication (f x g)(x) = f(x) x g(x)
Division (f/g)(x) = f(x)/g(x) g(x) ≠0
Nov 13­7:01 AM
Composite Functions
The output of the first function becomes the input for the second function.
Read as G of F of X
f(x) = x ­ 2
g(x) = x2 Find g(f(­5))
1. Evaluate the inner function f(x) first
2. Use the Result as the input of the outer function g(x)
Find f(g(­5))
Nov 13­7:09 AM
2
A27­6Notes.notebook
March 29, 2016
Example: Discount and % off
You have a Coupon for $5 off any item in a store.
The store is also having a 20% off sale.
Cost with 20% off
f(x) = x ­ .2x = .8x
Find g(f(x)) = 20% off first
Cost with Coupon for $5 off
g(x) = x ­ 5
Find f(g(x)) = $5 off first
How much more is any item if the Coupon is applied first?
Nov 13­7:28 AM
HW? 7­6 WS #2­22 All
Aug 19­6:25 AM
3