The acosh() function takes a single argument and returns the arc hyperbolic cosine of that value in radian.
The function is defined in <cmath> header file.
[Mathematics] cosh-1x = acosh(x) [In C++ Programming]
acosh() prototype [As of C++ 11 standard]
double acosh(double x); float acosh(float x); long double acosh(long double x); double acosh(T x); // For integral type
acosh() Parameters
The acosh() function takes a single mandatory argument which is greater or equal to 1.
If the argument is less than 1, a domain error occurs.
acosh() Return value
The acosh() function returns a value in the range [0, ∞].
If the argument passed to acosh() is less than 1, it returns NaN (not a number).
| Parameter | Return Value |
|---|---|
| x >= 1 | [0, ∞] |
| x < 1 | NaN |
Example 1: How acosh() function works in C++?
#include <iostream>
#include <cmath>
#define PI 3.141592654
using namespace std;
int main()
{
double x = 13.21, result;
result = acosh(x);
cout << "acosh(x) = " << result << " radian" << endl;
// result in degrees
cout << "acosh(x) = " << result*180/PI << " degree" << endl;
return 0;
}
When you run the program, the output will be:
acosh(x) = 3.27269 radian acosh(x) = 187.511 degree
Example 2: acosh() function with integral type
#include <iostream>
#include <cmath>
#define PI 3.141592654
using namespace std;
int main()
{
int x = 4;
double result;
result = acosh(x);
cout << "acosh(x) = " << result << " radian" << endl;
// result in degrees
cout << "acosh(x) = " << result*180/PI << " degree" << endl;
return 0;
}
When you run the program, the output will be:
acosh(x) = 2.06344 radian acosh(x) = 118.226 degree
