**FINDING THE DERIVATIVE OF A FUNCTION**

Graphmatica is able to perform symbolic differentiation on most common functions and to display the derivative of a given curve in both text and graphical formats. To differentiate a function, select it in the queue and then Choose **Find Derivative** from the Calculus menu. (If the function you want to use is not in the queue, you must graph it first.) The program will then manipulate its internal representation of the equation to produce its derivative, add the resulting equation to the queue, and immediately graph it.

Note that while the curve produced by this process will always be correct, the equation of the curve may not be very well simplified, especially for complex equations. Therefore, the best way to check a derivative you found by hand is to overlay its graph with what the Find Derivative function generates.

Finding the derivative is only supported for Cartesian, polar, and parametric functions. For relations such as equations containing `y^2`

, the derivative is only found for the function with the positive root. Also note that for an implicit function which the program can transform into an explicit function of y, but not x (e.g. x+y=y^2), the derivative found will be dx/dy, rather than dy/dx.

Finally, the derivatives of equations containing the following functions cannot be found, for the given reasons:

`int` | not a continuous function |

`abs` | not guaranteed to be a smooth function |

`rand` | not predictable, by design |

kSoft, Inc. ksoft@graphmatica.com Last updated: Sun 11 Jun 2017