ccosf, ccos, ccosl - cppreference.com (original) (raw)

Defined in header <complex.h>
float complex ccosf( float complex z );	(1)	(since C99)
double complex ccos( double complex z );	(2)	(since C99)
long double complex ccosl( long double complex z );	(3)	(since C99)
Defined in header <tgmath.h>
#define cos( z )	(4)	(since C99)

1-3) Computes the complex cosine of z.

Type-generic macro: If z has type long double complex, ccosl is called. if z has type double complex, ccos is called, if z has type float complex, ccosf is called. If z is real or integer, then the macro invokes the corresponding real function (cosf, cos, cosl). If z is imaginary, then the macro invokes the corresponding real version of the function cosh, implementing the formula cos(iy) = cosh(y), and the return type is real.

[edit] Parameters

[edit] Return value

If no errors occur, the complex cosine of z is returned.

Errors and special cases are handled as if the operation is implemented by ccosh(I*z).

[edit] Notes

The cosine is an entire function on the complex plane, and has no branch cuts.

Mathematical definition of the cosine is cos z =

[edit] Example

#include <stdio.h> #include <math.h> #include <complex.h> int main(void) { double complex z = ccos(1); // behaves like real cosine along the real line printf("cos(1+0i) = %f%+fi ( cos(1)=%f)\n", creal(z), cimag(z), cos(1)); double complex z2 = ccos(I); // behaves like real cosh along the imaginary line printf("cos(0+1i) = %f%+fi (cosh(1)=%f)\n", creal(z2), cimag(z2), cosh(1)); }

Output:

cos(1+0i) = 0.540302-0.000000i ( cos(1)=0.540302) cos(0+1i) = 1.543081-0.000000i (cosh(1)=1.543081)

[edit] References