Answer:
The principal square root of -4 is 2i.
Step-by-step explanation:
[tex]\sqrt{-4}[/tex] = 2i
We have the following steps to get the answer:
Applying radical rule [tex]\sqrt{-a} =\sqrt{-1} \sqrt{a}[/tex]
We get [tex]\sqrt{-4} =\sqrt{-1} \sqrt{4}[/tex]
As per imaginary rule we know that [tex]\sqrt{-1}=i[/tex]
= [tex]\sqrt{4} i[/tex]
Now [tex]\sqrt{4} =2[/tex]
Hence, the answer is 2i.
