Solve.
-$$x ^ { 4 } - 16 = 0$$
A) $\{ - 2,2 , - 2 i , 2 i \}$
B) $\{ - 4,4 , - 4 i , 4 i \}$
C) $\{ - 4,4 \}$
D) $\{ - 2,2 \}$

Question

Quizplus · Accepted Answer

This equation can be solved by factoring it as a difference of squares: $x^4 - 16 = (x^2)^2 - 4^2 = (x^2 - 4)(x^2 + 4) = (x - 2)(x + 2)(x^2 + 4)$. The roots are $x = 2, x = -2$ from the first two factors, and $x^2 + 4 = 0$ gives $x = \pm 2i$, thus the solution set is $\{-2, 2, -2i, 2i\}$.

Solve - x4−16=0x ^ { 4 } - 16 = 0x4−16=0

Solve
- $x ^ { 4 } - 16 = 0$