math functions?

[zaharaandfarah]

hi. 2 all
anyone can tell what is the wrong with this code? the result of this program is :
cos(60)=-0.952413
sin(60)=-0.304811

#include <iostream.h>
#include <math.h>
main()
{
 float x,y,z;
y=cos(60);
z=sin(60);
cout<<"cos(60)="<<y<<endl;
cout<<"sin(60)="<<z<<endl;
}

cheers

[Obsidian_496]

I don't see a problem there. I've been using Borland C++ for my home assignments, and your code compiled on it without errors. Then again, it is an outdated compiler, and you are probably using a different one.

Maybe you want to put getch() in the end, so that window does not close, when program is finished, and you can view the results?

[jonsca]

The math.h functions take an angle in radians. Use the conversion pi radians is to 180 degrees to convert your angles before sending them in.

[n.utiu]

math.h trigonometric functions take parameters in radians. To convert radians to degrees :
cos (60 degrees) is equivalent to

cos (PI*60/180)

PI - predefined constant in math.h

[jonsca]

PI - predefined constant in math.h

I think it's M_PI (although it may be redefined elsewhere).

[n.utiu]

I think it's M_PI (although it may be redefined elsewhere).

Yeah, sorry. The constant in cmath is M_PI.