Question

How do I graph an ellipse on a TI-84?

Answer 1

It is a rather onerous process to do that. First, you'd need to convert the equation to `y=` form, which means you'd get an ugly looking plus or minus square root function. Also, the processes involved in getting it to this form are very mistake-prone areas.

However, there is an app in the TI-84 called "Conics" (number 4 under apps) which does let you graph it very easily. Regrettably, this app doesn't have the graph features that the TI-84 has (i.e. Table, Calc Zeroes, etc), and hence is pretty useless unless you want a general picture to see what it looks like. However, I found that this app can be very useful if you forget the formulae for any of your conics. Use it wisely ;-)