Question

If F(x) = x²+1

What is f(f(x))?

A. X^4+2x^2+1
B. X^4+2x^2+2
C. X^4+2
D. X^4+1

Answer 1

B. x^4+2x^2+2

Explanation:

(x^2+1)^2+1

=(x^2+1)(x^2+1)+1

=(x^4+x^2+x^2+1)+1

=x^4+2x^2+2