power - exponentiation
double power(x, y)
double x, y;
Power returns x y,
i.e., x raised to the power y. If y is zero,
one is returned. If x is zero and y is non-negative, one
is returned. The actual exponentiation is performed with pow
(see exp(3)). The absolute values of x and y are
passed to pow. The signs of x and y are applied to
the result of pow to guarantee that it does not detect an error condition.
If y is negative, the reciprocal is taken.
If x is negative and y is odd, the value returned is negative.
If x is negative and y is even, the value returned is positive.
It is more efficient to square a value by multiplying it by itself.
It is more efficient to take the square root of a value with sqr(math).
This function implements exponentiation.
exp(3) in the UNIX Programmerís Manual
Error 11 (Division by zero) is generated if x is zero and y
Error 5 (Illegal function call) is generated if x is negative and
y is not an integer (mathematically).
The Basmark QuickBASIC Programmerís Manual