/C

# csinf, csin, csinl

Defined in header `<complex.h>`
`float complex       csinf( float complex z );`
(1) (since C99)
`double complex      csin( double complex z );`
(2) (since C99)
`long double complex csinl( long double complex z );`
(3) (since C99)
Defined in header `<tgmath.h>`
`#define sin( z )`
(4) (since C99)
1-3) Computes the complex sine of `z`.
4) Type-generic macro: If `z` has type `long double complex`, `csinl` is called. if `z` has type `double complex`, `csin` is called, if `z` has type `float complex`, `csinf` is called. If `z` is real or integer, then the macro invokes the corresponding real function (`sinf`, `sin`, `sinl`). If `z` is imaginary, then the macro invokes the corresponding real version of the function `sinh`, implementing the formula sin(iy) = i sinh(y), and the return type of the macro is imaginary.

### Parameters

 z - complex argument

### Return value

If no errors occur, the complex sine of `z`.

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

The sine is an entire function on the complex plane, and has no branch cuts. Mathematical definition of the sine is sin z =

 eiz-e-iz 2i

### Example

```#include <stdio.h>
#include <math.h>
#include <complex.h>

int main(void)
{
double complex z = csin(1);  // behaves like real sine along the real line
printf("sin(1+0i) = %f%+fi ( sin(1)=%f)\n", creal(z), cimag(z), sin(1));

double complex z2 = csin(I); // behaves like sinh along the imaginary line
printf("sin(0+1i) = %f%+fi (sinh(1)=%f)\n", creal(z2), cimag(z2), sinh(1));
}```

Output:

```sin(1+0i) = 0.841471+0.000000i ( sin(1)=0.841471)
sin(0+1i) = 0.000000+1.175201i (sinh(1)=1.175201)```
• C11 standard (ISO/IEC 9899:2011):
• 7.3.5.5 The csin functions (p: 191-192)
• 7.25 Type-generic math <tgmath.h> (p: 373-375)
• G.7 Type-generic math <tgmath.h> (p: 545)
• C99 standard (ISO/IEC 9899:1999):
• 7.3.5.5 The csin functions (p: 173)
• 7.22 Type-generic math <tgmath.h> (p: 335-337)
• G.7 Type-generic math <tgmath.h> (p: 480)

 ccosccosfccosl (C99)(C99)(C99) computes the complex cosine (function) ctanctanfctanl (C99)(C99)(C99) computes the complex tangent (function) casincasinfcasinl (C99)(C99)(C99) computes the complex arc sine (function) sinsinfsinl (C99)(C99) computes sine (sin(x)) (function) C++ documentation for `sin`