Whenever I type this C++ code segment, i get an answer of 1.32679e-06. Does anyone know why this happens, or how to make the cosine of pi divided by 2 equal zero? It's a radians measurement, not a degrees measurement.
using namespace std;
const double PI = 3.14159;
cout << "cos(PI / 2) = " << cos(PI / 2) << "\n\n";
It happens because you're using 3.14159 instead of the actual value of pi, which is a much longer and more precise number. 1.32679e-06 is the scientific notation of 0.00000132679, which is very close to zero. The answer is correct given the double
PI is not exactly equal to pi, so the cosine of (
PI / 2) is not equal to zero. Try using the
M_PI variable that comes with
<cmath> instead of defining a variable yourself.
EDIT: You could also try rounding it.