Question

The value of $\sqrt{(-1)}.\sqrt{(-1)}$ is:

• A. $-1$
• B. $+1$
• C. $\pm 1$
• D. None of these

Answer 1

The correct option is A $-1$

We define $\sqrt{-a}$ as the quantity which is being multiplied by itself (or) squared become equal to '- a'
So, $\sqrt{-a}\times \sqrt{-a}=(\sqrt{-a}{)}^2=-a$
$\therefore \sqrt{-1}\times \sqrt{-1}=-1$