Question

Find the roots of x^4 - 16 = 0.

√ x^4 = √ 16

x^2 = 4

√ x^2 = ± √ 4

2,-2

Answer 1

correct

or

(x^2+4)(x^2-4) = 0

x^2 + 4 = 0 --> no real solution
or
x^2 - 4 = 0
(x+2)(x-2) = 0
x = ±2