I have a small bit of code that should accept an input as a double and use that input value in an equation with tan() and cos()...but it doesn't work and I don't know why. Here's my code:

Code:

#include <stdio.h>
#include <math.h>
int main (void)
{
double theta = 0.0, sin_theta = 0.0;
printf ("Enter a number (theta) to be calculated: ");
scanf ("%lf", &theta);
sin_theta = (tan (theta)) * (cos (theta));
printf ("Tangent of theta times cosine of theta: %lf\n\n\n",
sin_theta);
return 0;
}

Any help is welcome. Thanks!