Thread: Graphing a function

Originally Posted by whiteowl

I need to graph F(x)=2X(X-3)(X+2) I know the graph will end up in Q1 And 3 and also know the X intercepts are -2, 0, and 3. I need to find the two vertex of the curves. How do I do this. Thanx

I presume you are using a calculator to determine this because otherwise this is a Calculus problem.

If you have anything in the TI series this should do for you.
Graph the function. Look at the toolbar above. There should be a "Math" option or something like it. (On the TI-92 it is F5.) Under that menu there are two options that say "Minimum" and "Maximum." Both functions will ask for bounds, so pick two points on either side of the vertex that won't overlap with the other one.

Other kinds of calculators probably use a similar routine.

Of course you can always do a binary search, but that takes a lot longer. Let me know if you need help with this.

-Dan

I wish I was using a calculator. The instructor did not go over how to find the vertex in class but when he assigned the homework there were about 12 problems like this. I can find all I need but the vertex which like I said he did not go over in class. He might be wanting just the general look of the graph with the X intercepts and if it bounces or crosses the axis. If it is that much over my head and need a graphing calculator the I bet he just wants a general look because he is totally agains calculators. Make sense? Thanx