Urgent TI-89 Titanium HELP NEEDED!

apples

OK, this is driving me nuts. I am learning how to use the calculator, and I can make perfect graphs for any function for x using the Y= Editor
For ex. f(x)=y="function"

But how do I make a a function for y? ex. f(y)=x="function"
I jus spent an hour reading the manual and TI-89Titanium for dummies. I can't find an answer.

If I convert the x function into a y function it won't be sufficient

because for a function like x=y^2
it would be y= ("under root")2
This would graph only half the function.


Please help me

Thank you,

George Jones

To graph x =f(y), switch to the parametric mode for graphing, and set xt1 = f(t) and yt1=t.

Your example becomes

xt1=t^2
yt1=t

In WINDOW, set, for example,

tmin = -2
tmax = 2
xmin = 0
xmax = 4
ymin = -2
ymax = 2

apples

This still doesn't give the correct graph. It's supposed to give a parabola, but it's only giving half of it. Still the same problem

it won't give anything for a negative y value.

George Jones

What I detailed in my previous post gives a full parabola on my TI-89. I am puzzled.

Did you use the values for Window that I gave?

apples

Bingo!
Got it.
Thanks a lot!

Btw, Do I have to set the minimum and maximum values every time in the WINDOW?

George Jones

In any graphing mode, including function and parametric modes, the minimum and maximum value s in WINDOW might have to be changed when moving from graph to graph. It depends on the individual situations; sometimes no change is necessary.

apples

All right. Thanks a lot!