Raise a number to a given power
#include <math.h> double pow( double x, double y ); float powf( float x, float y ); long double powl( long double x, long double y );
libm
Use the -l m option to qcc to link against this library.
The pow(), powf(), and powl() functions compute x raised to the power of y.
A domain error occurs if x = 0, and y ≤ 0, or if x is negative, and y isn't an integer. A range error may also occur.
The value of xy. For finite values of x less than 0 and finite non-integer values of y, these functions return NaN. The return value for a correct value that would cause underflow is 0.0.
If an error occurs, these functions return 0, but this is also a valid mathematical result. If you want to check for errors, set errno to 0, call the function, and then check errno again. These functions don't change errno if no errors occurred. |
#include <stdio.h> #include <stdlib.h> #include <math.h> int main( void ) { printf( "%f\n", pow( 1.5, 2.5 ) ); return EXIT_SUCCESS; }
produces the output:
2.755676
Safety: | |
---|---|
Cancellation point | No |
Interrupt handler | No |
Signal handler | No |
Thread | Yes |