Acos() - C library function Program

Declaration :

double acos(double x)

Explanation :

Purpose	The C library function double acos(double x) returns the arc cosine of x in radians.
Parameters	x ===> This is the floating point value in the interval [-1+1].
Return Value	This function returns principal arc cosine of x in the interval [0 pi] radians.
Exception

C Program : Example

The following example shows the usage of acos() function.

#include 
#include 
#define PI 3.14159265
int main ()
{
   double x, ret, val;
   x = 0.9;
   val = 180.0 / PI;
   ret = acos(x) * val;
   printf("The arc cosine of %lf is %lf degrees", x, ret);
   return(0);
}