4    return acosf((powf(a,2) + powf(b,2) - powf(c,2))/(2*a*b));
     9    return acosf((a*a + b*b - c*c)/(2*a*b));
    14    return acos((pow(a,2) + pow(b,2) - pow(c,2))/(2*a*b));
    19    return acos((a*a + b*b - c*c)/(2*a*b));
 double double_formula_pow(double a, double b, double c)
 
float formula_pow(float a, float b, float c)
 
double double_formula_mult(double a, double b, double c)
 
float formula_mult(float a, float b, float c)