Question

Solve for the roots of x in each of the equations below.
x^4 - 81 = 0

x^4 + 10x^2 + 25 = 0

x^4 - x^2 - 6 = 0

Answer 1

1. x=3, x=-3

2. 2 i sqrt(5), -i sqrt(5)

3. sqrt(3), -sqrt(3), i sqrt(2), -i sqrt(2)