# C++ sin()

The sin() function in C++ returns the sine of an angle (argument) given in radians.

This function is defined in <cmath> header file.

```[Mathematics] sin x = sin(x) [In C++ Programming]
```

## sin() prototype (As of C++ 11 standard)

```double sin(double x);
float sin(float x);
long double sin(long double x);
double sin (T x); // For integral type```

## sin() Parameters

The sin() function takes a single mandatory argument in radians.

## sin() Return value

The sin() function returns the value in the range of [-1, 1]. The returned value is either in `double`, `float`, or `long double`.

## Example 1: How sin() works in C++?

``````#include <iostream>
#include <cmath>

using namespace std;

int main()
{
double x = 0.439203, result;

result = sin(x);
cout << "sin(x) = " << result << endl;

double xDegrees = 90.0;

x = xDegrees*3.14159/180;
result = sin(x);

cout << "sin(x) = " << result << endl;

return 0;
}``````

When you run the program, the output will be:

```sin(x) = 0.425218
sin(x) = 1```

## Example 2: sin() function with integral type

``````#include <iostream>
#include <cmath>
using namespace std;

int main()
{
int x = -1;
double result;

result = sin(x);
cout << "sin(x) = " << result << endl;

return 0;
}``````

When you run the program, the output will be:

`sin(x) = -0.841471`