The graph programs plots real->real functions.

Functions are entered as expressions containing the variable x.
Press <Return> to draw the function.

You can draw several functions at the same time by entering a comma-separated
list of expressions.

Clicking the left mouse button zooms towards the point where you clicked.
Clicking the right mouse button zooms away from the point where you clicked.
Moving the mouse while the middle mouse button is pressed allows you to
zoom in to an arbitrary rectangular area.
Shift-clicking the left mouse button near a root finds the root.

Operators and functions supported are:

* / + - ^

sin cos tan exp log sqrt abs floor ceil tanh
cosh sinh gamma atan acos asin sgn theta

Author: Thomas Hallgren