Question

What is -square root of -100?

Answer 1

The square root of `-100` only exists as an imaginary number: `color(red)(+-10i)` where `color(blue)(color(red)i^2=-1)`

Explanation:

...and for those people who believe any reference to square root should imply only the primary square root, then you can drop the minus sign: `color(red)(+10i)`