MadCalc

MadCalc is a full featured graphing calculator application for your PC running Windows. With MadCalc you can graph rectangular, parametric, and polar equations.
Plot multiple equations at once. Change the colors of graphs and the background. Use the immediate window feature to evaluate complex multivariate expressions.
Teachers can use MadCalc to create handouts for your classroom. Students can use it instead of that tiny calculator screen while you are doing your calculus homework.
MadCalc supports all the commonly used functions including trigonometric functions, inverse trigonometric functions, hyperbolic functions, logarithms, and rounding and absolute value functions.
MadCalc allows you to export your work as bitmap files for printing or editing. MadCalc allows you to zoom in and out on graphs or set the scale in terms of x and y explicitly or scroll just by clicking on the graph and dragging it.
MadCalc provides all the essential graphing functionality without the complexity, cost, or overhead of something like Mathematica or MatLab.