<p>My calculator refuses to compute the minimum or maximum of a parabola. I'm using a Ti-83+ and have reset the calculator to factory defaults and it still won't work. Now I know this isn't hard to find my hand specially when a function is written in vertex form or standard form but it would be faster for me to compute info like this in the calculator using intercept form. Anybody out there know how to fix this thing? It only keeps giving me the value of Y when X is zero instead of computing the maximum or minimum of the parabola.</p>
<p>I don't know exactly what you're doing wrong - you press 2nd stat, then select either minimum or maximum, then move the cursor left of where the min/max is, press enter, move it right of the min/max, and then press enter twice. I'm guessing you're not moving the cursor left and right since that's an easy mistake to make.</p>
<p>Ummm I believe that is for some other type of stats.</p>
<p>For graphing parabolas after I enter something like y=3x(squared)-18x+20 and then click 2nd to trace(go into the calc menu) and then click 3 which is the minimum in this case for this graph. I get X=0 y=20. Now this is true point but the minimum is y=-7 when X=3.</p>
<p>Sounds like you're just calculating the zero (when x=0, y=some number), instead of the max/minimum. I have a TI-84+, but here's what I would do to find the minimum of a parabola:</p>
<p>2nd -> Trace(Calc) -> 3: minimum</p>
<p>I think I got it. You do move it to the left or right but that is under calculate and not stats. I eventually got this thing. It still isn't as accurate as doing it on paper. <em>sigh</em></p>