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<h1 id="firstHeading" class="firstHeading">ccosf, ccos, ccosl</h1> <table class="t-dcl-begin"> <tr class="t-dsc-header"> <th> Defined in header <code><complex.h></code> </th> <th> </th> <th> </th> </tr> <tr class="t-dcl t-since-c99"> <td> <pre data-language="c">float complex ccosf( float complex z );</pre>
</td> <td> (1) </td> <td> <span class="t-mark-rev t-since-c99">(since C99)</span> </td> </tr> <tr class="t-dcl t-since-c99"> <td> <pre data-language="c">double complex ccos( double complex z );</pre>
</td> <td> (2) </td> <td> <span class="t-mark-rev t-since-c99">(since C99)</span> </td> </tr> <tr class="t-dcl t-since-c99"> <td> <pre data-language="c">long double complex ccosl( long double complex z );</pre>
</td> <td> (3) </td> <td> <span class="t-mark-rev t-since-c99">(since C99)</span> </td> </tr> <tr class="t-dsc-header"> <th> Defined in header <code><tgmath.h></code> </th> <th> </th> <th> </th> </tr> <tr class="t-dcl t-since-c99"> <td> <pre data-language="c">#define cos( z )</pre>
</td> <td> (4) </td> <td> <span class="t-mark-rev t-since-c99">(since C99)</span> </td> </tr> </table> <div class="t-li1">
<span class="t-li">1-3)</span> Computes the complex cosine of <code>z</code>.</div> <div class="t-li1">
<span class="t-li">4)</span> Type-generic macro: If <code>z</code> has type <code><span class="kw4">long</span> <span class="kw4">double</span> <a href="http://en.cppreference.com/w/c/numeric/complex/complex"><span class="kw743">complex</span></a></code>, <code>ccosl</code> is called. if <code>z</code> has type <code><span class="kw4">double</span> <a href="http://en.cppreference.com/w/c/numeric/complex/complex"><span class="kw743">complex</span></a></code>, <code>ccos</code> is called, if <code>z</code> has type <code><span class="kw4">float</span> <a href="http://en.cppreference.com/w/c/numeric/complex/complex"><span class="kw743">complex</span></a></code>, <code>ccosf</code> is called. If <code>z</code> is real or integer, then the macro invokes the corresponding real function (<code>cosf</code>, <code><a href="http://en.cppreference.com/w/c/numeric/math/cos"><span class="kw670">cos</span></a></code>, <code>cosl</code>). If <code>z</code> is imaginary, then the macro invokes the corresponding real version of the function <code><a href="../math/cosh" title="c/numeric/math/cosh">cosh</a></code>, implementing the formula cos(iy) = cosh(y), and the return type is real.</div> <h3 id="Parameters"> Parameters</h3> <table class="t-par-begin"> <tr class="t-par"> <td> z </td> <td> - </td> <td> complex argument </td>
</tr>
</table> <h3 id="Return_value"> Return value</h3> <p>If no errors occur, the complex cosine of <code>z</code> is returned.</p>
<p>Errors and special cases are handled as if the operation is implemented by <code><a href="http://en.cppreference.com/w/c/numeric/complex/ccosh"><span class="kw805">ccosh</span></a><span class="br0">(</span>I<span class="sy2">*</span>z<span class="br0">)</span></code>.</p>
<h3 id="Notes"> Notes</h3> <p>The cosine is an entire function on the complex plane, and has no branch cuts. Mathematical definition of the cosine is cos z =</p>
<span><span>eiz+e-iz</span><span>/</span><span>2</span></span> <h3 id="Example"> Example</h3> <div class="t-example"> <div class="c source-c"><pre data-language="c">#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));
}</pre></div> <p>Output:</p>
<div class="text source-text"><pre data-language="c">cos(1+0i) = 0.540302-0.000000i ( cos(1)=0.540302)
cos(0+1i) = 1.543081-0.000000i (cosh(1)=1.543081)</pre></div> </div> <h3 id="References"> References</h3> <ul>
<li> C11 standard (ISO/IEC 9899:2011): </li>
<ul>
<li> 7.3.5.4 The ccos functions (p: 191) </li>
<li> 7.25 Type-generic math <tgmath.h> (p: 373-375) </li>
<li> G.7 Type-generic math <tgmath.h> (p: 545) </li>
</ul>
<li> C99 standard (ISO/IEC 9899:1999): </li>
<ul>
<li> 7.3.5.4 The ccos functions (p: 173) </li>
<li> 7.22 Type-generic math <tgmath.h> (p: 335-337) </li>
<li> G.7 Type-generic math <tgmath.h> (p: 480) </li>
</ul>
</ul> <h3 id="See_also"> See also</h3> <table class="t-dsc-begin"> <tr class="t-dsc"> <td> <div><a href="csin" title="c/numeric/complex/csin"> <span class="t-lines"><span>csin</span><span>csinf</span><span>csinl</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div> </td> <td> computes the complex sine <br> <span class="t-mark">(function)</span> </td>
</tr> <tr class="t-dsc"> <td> <div><a href="ctan" title="c/numeric/complex/ctan"> <span class="t-lines"><span>ctan</span><span>ctanf</span><span>ctanl</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div> </td> <td> computes the complex tangent <br> <span class="t-mark">(function)</span> </td>
</tr> <tr class="t-dsc"> <td> <div><a href="cacos" title="c/numeric/complex/cacos"> <span class="t-lines"><span>cacos</span><span>cacosf</span><span>cacosl</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div> </td> <td> computes the complex arc cosine <br> <span class="t-mark">(function)</span> </td>
</tr> <tr class="t-dsc"> <td> <div><a href="../math/cos" title="c/numeric/math/cos"> <span class="t-lines"><span>cos</span><span>cosf</span><span>cosl</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div> </td> <td> computes cosine (\({\small\cos{x} }\)cos(x)) <br> <span class="t-mark">(function)</span> </td>
</tr> <tr class="t-dsc"> <td colspan="2"> <span><a href="https://en.cppreference.com/w/cpp/numeric/complex/cos" title="cpp/numeric/complex/cos">C++ documentation</a></span> for <code>cos</code> </td>
</tr> </table> <div class="_attribution">
<p class="_attribution-p">
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