qt math support

[wysota]

I know what sin() is, but what I wanted to know, are stdmath and math.h SAME headers? Are both linked in glibc?

If you look at the code in the link, you'll see it includes <math.h> - sin(), cos(), etc. are just C functions, you can use them in C++ apps as well. <cmath> just embedds the function names into the std namespace (as J-P already explained) to avoid potential name clash.