Solution 10372: Calculating Numeric Derivatives on the TI-82.
How do I find the numeric derivative of an expression on the TI-82?
The example below will demonstrate how to calculate the numeric derivative of an expression on the TI-82.
Find the numerical derivative of x2-4X, when x=3.
1) Press [MATH] , to paste the nDeriv( command onto the home screen.
2) Input the expression x^2-4X. The screen will read:
3) After the expression, input [,] [x] [,]  [)] (x is the variable, and 3 is the value of the derivative. The screen will read:
4) Press [ENTER] to solve.
Please see the TI-82 guidebook for additional information.