# TI-83 plus graphing calculator help

## Recommended Posts

How do you find the vertex of a parabola using the calculator?

##### Share on other sites

Personally, I would plot it and observe where the point is

sure

##### Share on other sites

find where the first derivative = 0. i think you may have seen it as -b\2.

##### Share on other sites

Doesn't really help much if the person in question hasn't touched differentiation

As I said, plotting it will show you where the minimum point is. The other (slighty more) mathematical way of doing it is to work out where a line of zero tangent intersects the curve. And, of course, there's calculus if you've done that kind of thing already.

##### Share on other sites

Hit 2nd TRACE. If the parabola's vertex is at the bottom, hit "minimum" and if it's at the top, hit "maximum."

Now it will ask you for a left bound. Arrow over to the left of the vertex and hit enter. Now it asks you for right bound; move to the right of the vertex and hit enter. When it asks for a guess, just hit enter where you think the vertex is.

Voila, it spouts out the vertex.

##### Share on other sites

alright, thanks all.

## Create an account or sign in to comment

You need to be a member in order to leave a comment

## Create an account

Sign up for a new account in our community. It's easy!

Register a new account