Question:
#include "stdafx.h"
#include <cmath>
#include <iostream>
int main()
{
double d = 50.879840;
std::cout << cos(d) << std::endl;
return 0;
}
The program gives the result 0.817144 , although on any engineering calculator the result is 0.630948 , and this is correct. Where is the mistake?
Answer:
The cos
, sin
, and similar functions take a parameter in radians, not degrees.
Convert the value from degrees to radians, and everything will be correct:
double d = 50.879840;
std::cout << cos(d / 180 * Pi) << std::endl;