TI 89 - how do you graph sine and cosine?

Question

I just got a TI-89 and I'm not sure how to graph sines and cosines? Whenever I try to graph it, there is a line to the left and right of the screen. The middle part is entirely empty?

Answer 1

i have TI 84 so im not sure if this works for u but try change window(which is placed on the second left on the top, just under the screen)

if you are on degree

xmin = 0

xmax = 360

ymin=-1

ymax=1

if you are on radian

xmin=0

xmax =2pie

ymin=-1

ymax=1

u need to adjust the window depending on equations ur trying to graph but this works for normal cosine or sine functions like y=cos(x) and y=sin(xI)

Answer 2

Congrats on the TI-89, I find mine to be very useful.

As for the graphing, first in MODE, make sure that Graph is set to FUNCTION, and Angle to RADIAN. Then go to the Y= and put in the two graphs (sin(x) and cos(x)). Then in WINDOW (Diamond key then F2) make sure that you have the window to a decent setting...for trig functions maybe

xmin=-2 pi

xmax=2 pi

xscl=1

ymin=1.5

ymax=1.5

yscl=1

Then go to the graph (Diamond key, then F3)

If that doesn't work, I am not sure what the problem is.

Edit: The problem may be the RADIAN thing (I just switched from RADIAN to DEGREE and got exactly what you described. So to fix it all you probably have to do is press MODE, go to Angle and change it to RADIAN, then press Enter to exit the menu and save the setting.