Question

write the number \\(\sqrt{-81} - 5\\) in standard form.
use the keypad to enter your answer in the box.

the standard form of the number \\(\sqrt{-81} - 5\\) is \\(\boxed{}\\).

Explanation:

Step1: Simplify the square root

Recall that $\sqrt{-1}=i$, so $\sqrt{-81}=\sqrt{81 \times (-1)} = \sqrt{81} \times \sqrt{-1} = 9i$

Step2: Rearrange into standard form

Standard form of a complex number is $a+bi$, so rewrite the expression by placing the real part first.
$-5 + 9i$

Answer:

$-5 + 9i$