Perform the indicated operations and write the result in standard form.
-$$( - 4 - \sqrt { - 81 } ) ^ { 2 }$$
A) $- 65 + 72 \mathrm { i }$
B) $97 + 72 \mathrm { i }$
C) $16 + 81 \mathrm { i }$
D) $16 - 81 \mathrm { i }$

Question

Quizplus · Accepted Answer

First, simplify the square root: $\sqrt{-81} = 9i$. Then, $(-4 - 9i)^2 = (-4)^2 - 2(4)(9i) + (9i)^2 = 16 - 72i - 81 = -65 - 72i$.

Perform the Indicated Operations and Write the Result in Standard (−4−−81)2( - 4 - \sqrt { - 81 } ) ^ { 2 }(−4−−81​)2

Perform the Indicated Operations and Write the Result in Standard $( - 4 - \sqrt { - 81 } ) ^ { 2 }$