C Tutorial/math.h/acos

acos

Item Value Header file math.h Declaration float acosf(float arg);double acos(double arg);long double acosl(long double arg); Return The acos() returns the arc cosine of arg. Parameter The argument must be in the range -1 to 1.

<source lang="cpp">#include <math.h>

 #include <stdio.h>
 int main(void)
 {
   double val = -1.0;
   do {
     printf("Arc cosine of %f is %f.\n", val, acos(val));
     val += 0.1;
   } while(val<=1.0);
   return 0;
 }</source>