Answer:
B. X⁴+2X²+2
Step-by-step explanation:
If f(x) = x²+1, we are to find ff(x)
F(f(x)) = f(x²+1)
to get f(x²+1), we will have to substitute x as x²+1 in the function f(x) as shown;
F(x²+1) = (x²+1)²+1
Expand the expression
f(x²+1) = (x²+1)(x²+1)+1
f(x²+1) = (x⁴+x²+x²+1)+1
f(x²+1) = x⁴+2x²+1+1
f(x²+1) = x⁴+2x²+2
Hence f(f(x)) = x⁴+2x²+2
