Question

The roots of the equation $i{x}^2-4x-4i$ = 0 are

• A. 2 ,-2$i$
• B. 2$i$
• C. -2$i$, -2$i$
• D. 2$i$, 2$i$

Answer 1

The correct option is C

-2$i$, -2$i$

we have $i{x}^2-4x-4i$ = 0

⇒$x^2+4ix-4$ = 0 ⇒ $x^2+2ix+2ix-4$ = 0

⇒ ($x$ + 2$i$)($x$ + 2$i$) = 0 ⇒ $x$ = -2$i$, -2$i$