Question

The conjugate of $(4+5i{)}^2$ is

• A. $-9-40i$
• B. $-9+40i$
• C. $9-40i$
• D. $9+40i$

Answer 1

The correct option is A $-9-40i$

Let $z=(4+5i{)}^2$
Now,
$\Rightarrow z=4^2+(5i{)}^2+40i\Rightarrow z=16-25+40i\Rightarrow z=-9+40i\therefore \overline{z}=-9-40i$