Returns the result of the first argument raised to a fractional power. FPOWER(x,a,b) = x^(a/b).
Both a and b must be integers (whole numbers). This function is primarily useful for finding fractional powers of negative numbers. (The normal exponentiation operator (^) will not work in this case, as internally x^a is calculated as exp(a*ln(x)), and the logarithm of a negative number is undefined.)
The function returns an invalid argument error if:
b is equal to 0.
x is less than 0, b is even, and a is odd.