Question

If f(x)=x-7 and g(x)=x^3, what is G(f(x))?

A. x^3+x-7
B. x^3(x-7)
C. X^3-7
D. (x-7)^3

Answer 1

replace the 'x' in the formula for g(x) by f(x):-

g(f(x)) = (x-7)^3

Its D

Answer 2

D.
`(x-7)^3`

Explanation:

Given functions are,

`f(x) = x-7-----(1)`

`g(x)=x^3-----(2)`

Now,

`g(f(x))=g(x-7)` ( From equation (1) ),

`=(x-7)^3` ( From equation (2) ),

`\implies g(f(x)) = (x-7)^3`

Hence, Option D is correct.