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# Knowledge Base

## Solution 12162: Symbolic Derivative Example Using the TI-89 Family, TI-92 Family, and Voyage™ 200 Graphing Calculators.

### How do I find the symbolic derivative of an expression using TI-89 family, TI-92 family, and Voyage 200 graphing calculators?

The following instructions will give the syntax for and demonstrate finding the derivative of an expression using the TI-89 family, TI-92 family, and Voyage 200.

The syntax for d() is below:

d(expression,variable[,order])

Returns the first derivative of expression with respect to variable. The optional argument and accompanying comma are enclosed in brackets. If included, order must be an integer. If the order is less than zero, the result will be an anti-derivative.

Example: Find the derivative of wx3 with respect to x.

Solution:
1) Go to the home screen. Press [HOME] on the TI-89 family, [][HOME] on the TI-92 family, or [][CALC HOME] on the Voyage 200.
2) Press [2nd][8].
3) Input the rest of the expression w*x^3 (Be sure to enter the multiplication operation as denoted by the asterisk).
4) After the expression press [,][X][)] (since the derivative is with respect to X).
The screen will show: d(w*x^3,x).
5) Press [ENTER] for the result, which is 3x2w.

Please Note: If a numeric answer is received, there may be a number stored to the variable used. If this occurs the variables will need to be cleared.

To clear the variables on the TI-89 family:

1) Press [2nd][F6].
2) Choose 1: Clear a-z.
3) Press [ENTER].

To clear the variables on the TI-92 family or Voyage 200:

1) Press [F6].
2) Choose 1: Clear a-z.
3) Press [ENTER].

Now attempt the problem again.

Please see the TI-89 family, TI-92 family and Voyage 200 guidebooks for additional information.