You can use My Grapher to calculate a line tangent to a curve at a given point. Note: In this tutorial, “iPhone” refers to either an iPhone or an iPod touch.
1. iPad: Tap the + button and type in an equation for a curve. iPhone: Tap the list icon, then tap the + button to type in an equation for a curve.
2. If you graphed the equation shown above, you should get a graph like this:
3. iPad: Tap the gear icon, then tap Values. Choose Calculus from the two tabs at the top. iPhone: Tap and hold the graph, then tap Function Tool. Choose Calculus from the two tabs at the bottom. The options should look like this:
4. Tap X Value to choose which point the line should be tangent to. On iPhone, type the number in with the number keyboard.
5. Tap Done, and an equation should appear below the X Value option. Tap the equation to graph it.
I hope this helps you use My Grapher more effectively! Please leave a comment if you have any questions.