Defined in header <complex> | ||
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template< class T > complex<T> cos( const complex<T>& z ); |
Computes complex cosine of a complex value z.
| z | - | complex 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 std::cosh(i * z), where i is the imaginary unit.
The cosine is an entire function on the complex plane, and has no branch cuts. Mathematical definition of the cosine is cos z =
eiz+e-iz/2.#include <cmath>
#include <complex>
#include <iostream>
int main()
{
std::cout << std::fixed;
std::complex<double> z(1.0, 0.0); // behaves like real cosine along the real line
std::cout << "cos" << z << " = " << std::cos(z)
<< " ( cos(1) = " << std::cos(1) << ")\n";
std::complex<double> z2(0.0, 1.0); // behaves like real cosh along the imaginary line
std::cout << "cos" << z2 << " = " << std::cos(z2)
<< " (cosh(1) = " << std::cosh(1) << ")\n";
}Output:
cos(1.000000,0.000000) = (0.540302,-0.000000) ( cos(1) = 0.540302) cos(0.000000,1.000000) = (1.543081,-0.000000) (cosh(1) = 1.543081)
| computes sine of a complex number (\({\small\sin{z} }\)sin(z)) (function template) |
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| computes tangent of a complex number (\({\small\tan{z} }\)tan(z)) (function template) |
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(C++11) | computes arc cosine of a complex number (\({\small\arccos{z} }\)arccos(z)) (function template) |
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(C++11)(C++11) | computes cosine (\({\small\cos{x} }\)cos(x)) (function) |
applies the function std::cos to each element of valarray (function template) |
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C documentation for ccos |
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