Question

(Composite Functions): if f(x) = x^2 and g(x) = 2x+7, What is f[g(x)] when g(x) = 11

Answer 1

What is f[g(x)] when g(x) = 11 ?
Put g(x) = 11 in f[g(x)].
That is, find f(11).
f(x) = x^2
f(11) = 11^2 = 121.

Answer 2

That is incorrect. Solve for g(x) by making x =11. Thus g(x) =2(11) +7 or 29. Now take that solution and plug it into the x value of f(x) = x^2.
Thus it would be 29^2 is your answer.