This function is defined in <cmath> header file.
[Mathematics] cos x = cos(x) [In C++ Programming]
cos() prototype (As of C++ 11 standard)
double cos(double x); float cos(float x); long double cos(long double x); double cos(T x); // Here, T is an integral type.
cos() Parameters
The cos() function takes a single mandatory argument in radians.
cos() Return value
The cos() function returns the value in the range of [-1, 1]. The returned value is either in double
, float
, or long double
.
Note: To learn more about float and double in C++, visit C++ float and double.
Example 1: How cos() works in C++?
#include <iostream>
#include <cmath>
using namespace std;
int main()
{
double x = 0.5, result;
result = cos(x);
cout << "cos(x) = " << result << endl;
double xDegrees = 25;
// converting degrees to radians
x = xDegrees*3.14159/180;
result = cos(x);
cout << "cos(x) = " << result << endl;
return 0;
}
When you run the program, the output will be:
cos(x) = 0.877583 cos(x) = 0.906308
Example 2: cos() function with integral type
#include <iostream>
#include <cmath>
using namespace std;
int main()
{
int x = 1;
double result;
// result is in double
result = cos(x);
cout << "cos(x) = " << result << endl;
return 0;
}
When you run the program, the output will be:
cos(x) = 0.540302
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