Implicit Differentiation: Intro
In the applet below, note the graph of the equation .  
Please don't tamper with slider, input box, or checkbox quite yet.  Yet do so when prompted to by the questions below the applet.  
1.
Warm Up: Given the equation , use any one (or more) of the techniques of differentiation you've learned thus far to determine when .
2.
Click on the "Show Derivative at This Input Value" checkbox to check your work. Does what you see surprise you? Why does this (the fact that there are 2 possible values for ) occur?
Feel free to drag either of the gray points around.  You can also change the radius of the circle as well.