1. Combinations of Functions
Ch 1.5
Combinations of Functions

2. When you come in…
Start by getting out your Practice Test and checking answers with your group. When you are done make a pile in the center of your desk so I can collect.
Then get out your green Larson notebook!

3. CH 1.5 Sum, difference, product, Or quotient
All real numbers that are common to the domains of f and g.

4. EX: Let f(x) = 2x + 1 and g(x) = x² + 2x -1
a) Find (f+g)(x) b) Find (f-g)(x) c) Find (f*g)(x) d) Find ( 𝑓 𝑔 )(x)

6. What is the best deal you Have gotten at a retail store?
Activity 1.5 NBPG #32
Discuss in your group….
What is the best deal you
Have gotten at a retail store?
40% off?
$20 off?
What was the item?

7. Coupon Activity
Just #1-9

9. f(x) g(x) f(g(x)) f(g(x))
The set of all x in the domain of g such that g(x) is in the domain of f.
f(g(x))
What is domain of each?
* f(g(x)) and g(f(x)) do not generally equal each other

10. Operations W.S

11. Warm Up (In Green Larson NB)
When you walk in…
Check HW with your group. I will come around and answer questions and do some on the board.
Highlight # 51. Then start Warm Up
Warm Up (In Green Larson NB)

12. EX 3: Find the Domain of the Composite Function f(g(x))
F(x) = x² + 1
G(x) = 𝑥
It might appear that the domain is all reals but because domain of f is all real numbers and g is [-3,3] the domain of the composite is also [-3,3]

14. Extra Example – Composition of Functions
Method 1:
Method 2:
There are several ways people write the solutions to these problems. Some people like one more than the other. Look at the examples here and write down the way that makes the most sense for you.
Immediately replace f(x) into function
Then plug in -5