It is easy and fun to draw graphs of curves with the Java graphics library. Simply draw 100 line segments joining the points (x, f(x)) and (x + d, f(x + d)), where x ranges from xmin to xmax and d = (xmax − xmin)/100.
Draw the curve f(x) = 0.00005x3 − 0.03x2 + 4x + 200, where x ranges from 0 to 400 in this fashion.
Here is a sample program output: