## dy/dx command

The dy/dx command finds a numeric derivative, which approximates the first derivative
of an expression with respect to a variable at the trace cursor location while viewing a graph.

While viewing the graph of a function, press
to view the CALCULATE menu.

Press .

If more than one function is graphed, use
to select the desired
curve and then use
to trace the curve to the point for which the value of the derivative is needed.

**Note:** If the cursor cannot be placed close enough to the desired point, use the ZOOM
feature and repeat the process.

Pressing will display the value (or approximate value) of dy/dx at the point.

**Note:** The value of the derivative is found by computing the slope of the line
through the points and where
.