posted by Miley .
why is the answer to this question no real root?
Because -81^3 is a negative number. If you take a 1/4 root of any negative number (which is the same thing as taking a square root twice), you get imaginary or complex (real + imaginary) numbers.
the third power of -81 is a negative number
you can not take a square root of a negative number and get a real number.
(1/4) power is square root of square root.