Compositions using functions

Question

. Complete the compositions below given the following functions:

g(x)=x+4 d(x)={(2,1)(3,5)(−4,2)(−3,1)} t(x)=2x2 +3x−1

1. d(2) 2. g(-3) 3. t(x)= 8 4. t(g(x)) 5. Explain if d(x) is a function 6. Range of d(x)

Answer 1

f(x) is the "same" as y. What is y if x = whatever is in the parentheses.

What value of y does d(x) have when x = 2?

For the others, take -3, and or the other function and plug it in for x.

f(x) = x²

g(x) = x + 2

f(g(3)) = (3 + 2)² = 25

A function means that every x value calculates to only one y-value. {(2,0),(2,-1),(3,4)} is not a function.

The range is the list of your x-values. In the above set of points, the range is x = {2,3}. The domain is y = {0,-1,4}

Go.