Provide an Appropriate Response $\mathrm{a}<0$ , Then $\sqrt{-\mathrm{a}}=\mathrm{i} \sqrt{\mathrm{a}}$

True/False

Provide an appropriate response.
-If $\mathrm{a}<0$ , then $\sqrt{-\mathrm{a}}=\mathrm{i} \sqrt{\mathrm{a}}$ .