Solve the equation. (Find only the real solutions. Enter your answers as a comma-separated list.) x4 - 8x2 + 7 = 0

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