# C++ sin() Function

### The sin function in C++

• sin() is the built-in function in C++
• This function is defined in the <cmath> library – you have to include this in the header in order to use it.
• The sin() function takes one argument i.e. a number which is angle and it returns the sine of angle x radians.
• The return value is of double type i.e. sine of the given argument x (radians)

sin(x);

### An example of using sin() function

In the first example, we simply provide a value to the sin() function and assign the return value to a double-type variable. Then we displayed the result as follows:

```#include <iostream>

#include<cmath>

using namespace std;

int main()

{

double ang=1.04;

cout<<"Sine of an 1.04 = "<<sin(ang) <<"\n\n";

return 0;

}```

Result:

### Taking user input for sin()

As you run this C++ program, it asks you to enter the angle given in radians. Then sin() function is used to get the sine and we will display the result:

```#include <iostream>

#include<cmath>

using namespace std;

int main()

{

double ang;

cout << "Enter angle (in radians) to get sine : ";

cin >> ang;

cout<<"Sine of " <<ang  <<"= " <<sin(ang) <<"\n\n";

return 0;

}```

Sample result:

### Using negative value example

For this example, we assigned a negative value to the sin() function.

```#include <iostream>

#include<cmath>

using namespace std;

int main()

{

//negative angle

double ang = -45;

return 0;

}```

Output:

##### Author - Atiq Zia

Atiq is the writer at jquery-az.com, an online tutorial website started in 2014. With a passion for coding and solutions, I navigate through various languages and frameworks. Follow along as we solve the mysteries of coding together!