Question

F(x) = x²+1
What is f(f(x))?

Answer 1

f(f(x)) = x⁴ + 2x² + 2

Explanation:

if f(x) = x² + 1, then f(f(x)) is equal to:

f(x)² + 1

= (x² + 1)² + 1

= x⁴ + 2x² + 1 + 1

= x⁴ + 2x² + 2