Question 87471
I believe what you mean is {{{ root(3,-125)}}}.


The answer is -5, since if you take -5 and cube it (that is {{{(-5)^3}}}), you get -125.  


It is important to realize that the cube root of a negative number is a negative number, but the SQUARE root of a negative number is not possible in the real numbers.  If you have studied imaginary numbers (or complex numbers!), then a square root of a negative is an imaginary number (involving the letter "i")!


R^2  Retired from SCC