In this C++ tutorial, you will learn how to find the tangent of an angle using tan() function of cmath, with syntax and examples.

## C++ tan()

C++ tan() returns tangent of angle given in radians.

### Syntax

The syntax of C++ tan() is

`tan(x)`

where

Returns

The return value depends on the type of value passed for parameter x. The return value of tan(x) is

• double if x is double.
• float if x is float.
• long double if x is long double.

The synopsis of tan() function is

```double tan(double x);
float tan(float x);
long double tan(long double x);
double tan(T x); // for integral type argument values```

tan() is a function of cmath library. Include cmath library in the program, if using tan().

### Example

In this example, we read an angle value into x, from the user, and find the tangent of this angle using tan() function.

C++ Program

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

int main() {
float x;
cout << "Enter an angle (in radians) : ";
cin >> x;

double result = tan(x);
cout << "tan(" << x << ") : " << result << endl;
}```

Output

```Enter an angle (in radians) : 1.5
tan(1.5) : 14.1014
Program ended with exit code: 0```
```Enter an angle (in radians) : 0
tan(0) : 0
Program ended with exit code: 0```

### Conclusion

In this C++ Tutorial, we learned the syntax of C++ tan(), and how to use this function to find the tangent of an angle, with the help of examples.