# The value of $\sqrt i+\sqrt{-i}$ = ?

(A) 0 (B) $\sqrt 2$ (C) 2 (D) $\large\frac{1}{\sqrt 2}$

Toolbox:
• $\sqrt {i}=\pm\large\frac{1+i}{\sqrt 2}$
• $\sqrt {-i}=\pm\large\frac{1-i}{\sqrt 2}$
$\sqrt i+\sqrt {-i}=\large\frac{1+i}{\sqrt 2}+\frac{1-i}{\sqrt 2}$
$\large\frac{2}{\sqrt 2}$$=\sqrt 2$