# [SOLVED] TI-89 Titanium: Drawing a Tangent Line

• Jul 4th 2008, 11:39 AM
tupac
[SOLVED] TI-89 Titanium: Drawing a Tangent Line
Can you tell me what to press if i want to draw a tangent at x=1, and the equation is y=x^2?(Crying)

I know how to graph the function(Smirk), i just need help with drawing the tangent.

Thanks.
• Jul 4th 2008, 12:13 PM
galactus
Here is a screen capture from my 92. They are essentially the same.

Graph what you want, then press F5. You will see a drop down list. Locate Tangent. I think it is option A. It will ask where, type 1, then hit ENTER.
• Sep 2nd 2008, 08:01 PM
therealdealsays
i have this same problem too... i tried that, and then typed in one after graphing the first function and selecting tangent from the drop down list. i pressed enter and nothing graphed, but it said y=2.x-1

what does that mean?

and how do you get the line to be drawn tangent to the parabola?
• Sep 22nd 2008, 12:58 AM
earboth
Quote:

Originally Posted by therealdealsays
i have this same problem too... i tried that, and then typed in one after graphing the first function and selecting tangent from the drop down list. i pressed enter and nothing graphed, but it said y=2.x-1

what does that mean?

and how do you get the line to be drawn tangent to the parabola?

If you have done it as you described it then you used the wrong order. I've attached screen-shots to show you what you should do.

By the way: y = 2x-1 is the equation of the tangent to the parabola at the point T(1, 1)