Is there a way to search a table for a specific value of x or y on the TI-84 Plus. For example, if I graph a function and want to know the y value for this function is when x=1000, is there an easier way to find this value than taking the time to scroll all the way down to x=1000 in the table?

There are two ways you can do that.



Graphically:

Once the graph is drawn you can use the trace function b y pressing
TRACE. With the right and left arrows you can move along the curve. The
cursor will move by increments of Delta X, so some points you may be
interested in may not appear.

To remedy the situation you can just type in a value of X that is inside
the range Xmin , Xmax and press ENTER and the calculator will display
the corresponding Y value. This will work only for points inside the
interval Xmin, Xmax.



NUMERICALLY

To obtain Y-values outside the Xmin, Xmax interval you can use the fact
that Y1, for example, is already defined, and ask the calculator to
find a Y-value for you.



Say you want Y1 for X=1000.

In main computer screen you type in 1000 [STO>] [X, T, theta,n] [ENTER]


Calculator echoes the value 1000.


Press [VARS][right arrow >][Y-Vars][1:Function]


A list of Yx variables is displayed.


Select the one corresponding to the function of interest, say Y1, and press ENTER.


Variable echoes on main screen as Y1.


Press [ENTER] to calculate it at the value you stored in the variable X (1000).


If you want another value, just repeat the steps starting from storing a value in X etc.