Functions and domain

Question

Given f(x)= (0,2) (1,3) (2,4) (3,5) and g(x) = (2,-1) (3,0) (4,1) (5,2) 

 

Find (fog)(x) and its domain. 

 

Im really confused on how to solve this.

Answer 1

Start with the "inputs" of g(x)

g(2) = -1   this number becomes the input of f(x)

f(-1) no value

 

g(3) = 0

f(0) = 2

(f o g)(3) = 03, 4, 

 

g(4) = 1

f(1) = 3

(f o g)(4) = 3

 

g(5) = 2

f(2) = 4

(f o g)(5) = 4

 

The domain for (f o g)(x) is {3, 4, 5}