Question:
Find the modulus of each of the following:
$(3+\sqrt{-5})$
Solution:
Given: $z=(3+\sqrt{-5})$
The above can be re - written as
$z=3+\sqrt{(-1) \times 5}$
$z=3+i \sqrt{5}\left[\because i^{2}=-1\right]$
Now, we have to find the modulus of (3 + i√5)
So, $|z|=|3+i \sqrt{5}|=\sqrt{(3)^{2}+(\sqrt{5})^{2}}=\sqrt{9+5}=\sqrt{14}$
Hence, the modulus of $(3+\sqrt{-5})$ is $\sqrt{14}$