The **`cosh()` function** returns the hyperbolic cosine of a number. To be more specific, it returns the hyperbolic cosine of a number in the radian float value. 

Figure 1 shows the mathematical representation of the `cosh()` function.


> Note: The `math.h` header file is required for this function.


# Syntax
```c
double cosh(double num)
```
# Parameter
This function requires a `number` that represents an `angle` in `radians` as a parameter.

In order to convert `degrees` to `radians`, use the following formula:
```c
radians = degrees * ( PI / 180.0 )
```

# Return value
`cosh()` returns the `hyperbolic cosine` of a number `(radians float value)` that is sent as a parameter.

# Example


#include<stdio.h>
//header file
#include<math.h>

int main() {
    //positive number in radians
    printf("The hyperbolic cosine of %lf is %lf \n", 2.3, cosh(2.3));

    // negative number in radians
    printf("The hyperbolic cosine of %lf is %lf \n", -2.3, cosh(-2.3));

    //converting the degrees angle into radians and then applying cosh()
    // degrees = 90.0
    // PI = 3.14159265
    // result first converts degrees to radians then apply cosh
    double result=cosh(90.0 * (3.14159265 / 180.0));
    printf("The hyperbolic cosine of %lf is %lf \n", 90.0, result);


}

What is cosh() in C?

Returns hyperbolic cosine of a radian value; use math.h. Convert degrees to radians with degrees * ( PI / 180.0 ).