Question

What are the real and complex solutions of the polynomial equation x^4+3x^2-4

A. -1,1
B. 1,2i
C. -1,1,-2,2
D. -1,1,-2i,2i

Answer 1

Answer

-1,1,-2i,2i

Answer 2

Answer: (D) -1,1,-2i,2i

Step-by-step explanation:

`x^4+3x^2-4 = 0\\x^2 \rightarrow z\\z^2 + 3z -4 = 0 \\z_1 = -4\\z_2 = 1\\x_(1,2) = \pm√(-4)=\pm 2 i\\x_(3,4) = \pm 1`