Tap the blue circles to see an explanation.
| $$ \begin{aligned}(-4i)^2& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}16i^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}-16\end{aligned} $$ | |
| ① | $$ \left( -4i \right)^2 = (-4)^2i^2 = 16i^2 $$ |
| ② | $$ 16i^2 = 16 \cdot (-1) = -16 $$ |