Answer: x=0 or x= plus or minus 2
Step-by-step explanation:
g(x)=x^4-8x^2+7
Critical numbers are the numbers where the first derivative is zero
g'(x)=4x^3-16x+0
=4x^3-16x
g'(x)=0
Implies
4x^3-16x=0
4x(x^2-4)=0
4x=0 OR x^2-4=0
x=0 or x^2=4
x=0 or x= plus or minus 2
