I graphed Y=tan(x) on two TI-84 calculators and they're both wrong! one shows a straight diagonal graph, and the other looks similar to an ordinary tangent graph but it's wrong!

Is it somehow preventing you from graphing, or are you simply not getting the graph you expect?

Most likely you have the angular mode set wrong. You probably want it set to radians. Press MODE, move to the third line, highlight RADIAN, press ENTER, then 2ND [QUIT].

If it's not the angular mode, please reply to this post and give an example or two.

If the angle unit is set to degrees and you use the standard window dimensions (Xmin=-10, Xmax=10) then all you will see is a straight line: Between 0 and 10 degrees, the sine is approximately equal to 0 and the cosine is about 1.

To see the features of the trigonometric functions you must do one of the following

1. Set angle to degree but set window dimensions to span the domain -180 to 180 or larger.
   
2. Set windows dimensions to the standard -10, 10 range but set angle degree to radians

Make sure you have the angular mode set to radians. In degree, the graph of sine(x) is nearly a straight line for small values of x.

Make sure your x and y limits are big enough to show most of the graph.

You need to fix your graph so that it shows the correct y-axis and x-axis.
It works best if you press the zoom button and then scroll to find the ZoomFit option.
Then the graph should show up.

Having gone over a month without a response to my query, I assume it was a matter of the angular mode setting

Press the Y= key. Move to the equation in question, then press left-arrow repeatedly until the cursor is at the far end of the line. Press ENTER repeatedly to cycle through the different graph styles. The default is the four dots in a diagonal line from upper-left to lower-right.

Ok, try these two things and you should be just fine.
1.) Check your range for your graph. It is possible that the range you are using isnt large enough to show the curve. Also try using Z-fit vs Z-st. These are options that your calculator will give you once the equation is graphed.
2.) Place a parenthesis around the 2x, make sure that you and the calculator are both using the same order of operations. This move mill ensure that the calculator will multiply the variable, x, by two and then do the exponential.
This should do it!
Happy Graphing!

go to:


mode
select DEGREE rather than RADIAN three lines down.

Just passing by, make sure you aren't zoomed in or panned away from the axis when you look. Check to see if there is some way you could be referencing a matrix. I can pull up a similar error by trying to pull a value out of a non-existant slot. I got my first TI 2 days ago, so I probably don't know as much as you.