Answer
$3i\sqrt 7$
Work Step by Step
Solve $\sqrt{-63}$
As per square root property, we have $\sqrt{63}=\sqrt{9 \cdot 7}=\sqrt{3^2} \cdot \sqrt 7= 3\sqrt 7$
Thus,
$\sqrt{-63}=3\sqrt 7\sqrt {-1}$
Since, $i^2=-1$ and $\sqrt {-1}=i$
Hence, $\sqrt{-63}=3i\sqrt 7$
