Question

Help my brain is overloading!!!

Given f(x)= x^2-2x-1 find f(x^2+3)

I got x^4-2x^2+2

Answer 1

\[f(x)= x^{2}-2x-1 find f(x^{2}+3)\]

Answer 2

Replace x in f(x) with x^2 + 3
f(x) = x^2 - 2x -1 becomes
:x^2 + 3)^2 - 2(x^2 + 3) - 1

Answer 3

the official answer is \[x ^{4} -4x ^{2}+2\] I dont know why its a 4 instead of a 2