Best way to render a graph?

I'm finally taking calc in grade 12 now, and I'm really finding a lot of the stuff interesting, and I was thinking of making a program that can graph equations and find the tangents and things like that, along with the other things we learn as the semester progresses. I'm planning on using my OST2 math parser which has all the mathematical support for equations that I'll need, but mainly what I was wondering was what would be the best way to go about rendering graphs in windows?

I was thinking of maybe having a win32 window with an OpenGL instance inside of the window, along with edit boxes built in to the window for typing in the equations and such.

However, would it be better to use the win32 drawing functions instead? The GL version would merely render the frame once every time it needed to be updated and theoretically it would be easiest to implement as far as rendering goes. So...basically, should I use win32's drawing or OpenGL's rendering?