Question

Solve for the roots in the equation below.

x4 + 3x2 - 4 = 0

Answer 1

Answer: x = {1, -1, 2i, -2i}

Explanation:

x⁴ + 3x² - 4 = 0

∧

-1 +4 = 3 this works!

(x² - 1)(x² + 4) = 0

x² - 1 = 0 and x² + 4 = 0

x² = 1 and x² = -4

x = ±1 and x = ± 2i

x = 1, -1 and x = 2i, -2i