# What is the square root of -144?

12*i* where *i* is the square root of -1

Take the square root of +144, then add "i" at the end - where "i" is the imaginary unit.

### What is the negative square root of -144?

The negative square root of -144 is -12i - that is -12 times the square root of minus 1, ie √-144 = 12√-1. The above is a complex number, which I suspect is not the answer you wanted; there is no real number that is the square root of a negative number If you wanted the negative square root of 144, then it is -12.