funtool

Function calculator

Description

The funtool app is a visual function calculator that manipulates and displays functions of one variable. At the click of a button, for example, funtool draws a graph representing the sum, product, difference, or ratio of two functions that you specify. funtool includes a function memory that allows you to store functions for later retrieval.

Open the funtool App

At startup, funtool displays graphs of a pair of functions, f(x) = x and g(x) = 1. The graphs plot the functions over the domain [-2*pi, 2*pi]. funtool also displays a control panel that lets you save, retrieve, redefine, combine, and transform f and g.

Control panel of the funtool app

The top of the control panel contains a group of editable text fields.

f=	Displays a symbolic expression representing `f`. Edit this field to redefine `f`.
g=	Displays a symbolic expression representing `g`. Edit this field to redefine `g`.
x=	Displays the domain used to plot `f` and `g`. Edit this field to specify a different domain.
a=	Displays a constant factor used to modify `f` (see button descriptions in the next section). Edit this field to change the value of the constant factor.

funtool redraws f and g to reflect any changes you make to the contents of the control panel's text fields.

The bottom part of the control panel contains an array of buttons that transform f and perform other operations.

The first row of control buttons replaces f with various transformations of f.

df/dx

Derivative of f

int f

Integral of f

simplify f

Simplified form of f, if possible

num f

Numerator of f

den f

Denominator of f

1/f

Reciprocal of f

finv

Inverse of f

The operators int f and finv can fail if the corresponding symbolic expressions do not exist in closed form.

The second row of buttons translates and scales f and the domain of f by a constant factor. To specify the factor, enter its value in the field labeled a= on the calculator control panel. The operations are

f+a	Replaces `f(x)` by `f(x) + a`.
f-a	Replaces `f(x)` by `f(x) - a`.
*fa**	Replaces `f(x)` by `f(x) * a`.
f/a	Replaces `f(x)` by `f(x) / a`.
f^a	Replaces `f(x)` by `f(x) ^ a`.
f(x+a)	Replaces `f(x)` by `f(x + a)`.
*f(xa)**	Replaces `f(x)` by `f(x * a)`.

The first four buttons of the third row replace f with a combination of f and g.

f+g	Replaces `f(x)` by `f(x) + g(x)`.
f-g	Replaces `f(x)` by `f(x)-g(x)`.
*fg**	Replaces `f(x)` by `f(x) * g(x)`.
f/g	Replaces `f(x)` by `f(x) / g(x)`.

The remaining buttons on the third row interchange f and g.

g=f	Replaces `g` with `f`.
swap	Replaces `f` with `g` and `g` with `f`.

The first three buttons in the fourth row allow you to store and retrieve functions from the calculator's function memory.

Insert	Adds `f` to the end of the list of stored functions.
Cycle	Replaces `f` with the next item on the function list.
Delete	Deletes `f` from the list of stored functions.

The other four buttons on the fourth row perform miscellaneous functions:

Reset	Resets the calculator to its initial state.
Help	Displays the online help for the calculator.
Demo	Runs a short demo of the calculator.
Close	Closes the calculator's windows.