Updated: October 26, 2022 |
Compute the cosine of an angle
#include <math.h> double cos( double x ); float cosf( float x ); long double cosl( long double x );
Your system requirements will determine how you should work with these libraries:
These functions compute the cosine of x radians.
To check for error situations, use feclearexcept() and fetestexcept(). For example:
The cosine of x.
If x is: | These functions return: | Errors: |
---|---|---|
±0.0 | 1.0 | — |
±Inf | NaN | FE_INVALID |
NaN | NaN | — |
These functions raise FE_INEXACT if the FPU reports that the result can't be exactly represented as a floating-point number.
#include <stdio.h> #include <math.h> #include <fenv.h> #include <stdlib.h> int main( void ) { double value; int except_flags; feclearexcept(FE_ALL_EXCEPT); value = cos( M_PI ); printf( "The cosine of pi is %f\n", value ); except_flags = fetestexcept(FE_ALL_EXCEPT); if(except_flags) { /* An error occurred; handle it appropriately. */ } return EXIT_SUCCESS; }
produces the output:
value = -1.000000
Safety: | |
---|---|
Cancellation point | No |
Interrupt handler | Yes |
Signal handler | Yes |
Thread | Yes |