The n-th root of a number x, is a number r so that rn= x. In modern notation n-th root is written as or x1/n. Typically root degree n is an integer larger or equal to 2. For n=2 the result is called square root while for n=3 cube root. Any non-zero number has n distinct roots of n degree, either real or complex ones. If n is even, there are two real n-th roots of a real x, only if x is positive. These two roots are opposites and the positive one is called principal root. If x is negative and n is even, all roots are complex numbers. On the other hand, if n is odd, there is always a real n-th root for any real x (positive or negative). The n-th roots of 0 are all 0.
The derivative of the principal n-th root function is:
The integral of the n-th root function is given by: