Solve for x:
x^4-4 x^2 = 0
The left hand side factors into a product with three terms:
x^2 (x-2) (x+2) = 0
Split into three equations:
x-2 = 0 or x^2 = 0 or x+2 = 0
Add 2 to both sides:
x = 2 or x^2 = 0 or x+2 = 0
Take the square root of both sides:
x = 2 or x = 0 or x+2 = 0
Subtract 2 from both sides:
Answer: | | x = 2 or x = 0 or x = -2
