C library function atanh() usage and example

C Standard Library <math.h>

The atanh() function returns the inverse hyperbolic tangent of the radian number (the value of the inverse hyperbolic tangent).

The atanh() function takes a single parameter (-1≤x≥1), and returns the arc hyperbolic tangent value in radians.

The atanh() function is included in the <math.h> header file.

atanh() prototype

double atanh(double x);

To find the hyperbolic arctangent of types int, float, or long double, you can use the cast operator to explicitly convert the type to double.

　int x = 0;
　double result;
　result = atanh(double(x));

Additionally, C99Two functions atanhf() and atanhl() are introduced in C, which are specifically used for float and long double types.

float atanhf(float x);
long double atanhl(long double x);

atanh() parameter

The atanh() function takes a single parameter (-1and less than or equal to1parameter.

Example1atanh() function with different parameters

#include <stdio.h>
#include <math.h>
int main()
{
　　　　//PI constant
　　　　const double PI =　　3.1415926;
　　　　double x, result;
　　　　x =　　-0.5;
　　　　result = atanh(x);
　　　　printf("atanh(%.2f) = %.2lf radians\n", x, result);
　　　　//Convert radians to degrees
　　　　result = atanh(x);*180/PI;
　　　　printf("atanh(%.2f) = %.2lf degree\n", x, result);
　　　　//Parameter is out of range
　　　　x =　3;
　　　　result = atanh(x);
　　　　printf("atanh(%.2f) = %.2lf", x, result);
　　　　return 0;
}

Output Result

atanh(-0.50) =　-0.55　radians
atanh(-0.50) =　-31.47　degrees
atanh(3.00) = nan

C Standard Library <math.h>