Descartes

Displays graphs of algebraic functions in a variety of forms. These include polar and cartesian co-ordinates, Parametric and intrinsic functions. A wide range of functions are built-in, from simple trig and hyperbolic functions to things such as the ceil and gamma functions. On-screen HTML Help is bulit-in. Functions can be defined such as f(x)= 1 + xThese can be of unlimited complexity, and can refer to other functions such asg(x) = f(x) + 2*xOther variables can be set up, so we can define for examplef(x) = m*x + cand then vary m and c and see the change to the graph. It will also handle differentiation, integration, sums and products of series. It will deal with Maclaurin and Fourier Series, such as a Fourier approximation to a square wave. The graph limits can be altered in various ways - zoom in and out, center, left right up down and direct entry. Mouse wheel does zoom in and out. A chord can be displayed on a function, with the slope of the chord calculated and displayed.