# Evaluate a Sequence on the TI-83 Plus

You can use the TI-83 Plus to evaluate the graph of a sequence. To evaluate a sequence at a specified value of *n*, follow these steps:

Graph the sequences in a viewing window that contains the specified value of

*n*.To get a viewing window containing the specified value of

*n*, that value must be betweenand*n*Min.*n*MaxSet the Format menu to ExprOn and CoordOn.

Press [2nd][TRACE] to access the Calculate menu.

Press [1] to select the value option.

Enter the specified value of

*n*.To do so, use the keypad to enter the value of

*n.*If you make a mistake when entering your number, press**[CLEAR]**and re-enter the number.Press [ENTER].

What you see on the screen depends on the format used to produce the graph. The formats are as follows:

**Time format:**After you press**[ENTER]**, the first highlighted sequence in the Y= editor appears at the top of the screen, the cursor appears on the graph of that function at the specified value of*n*, and the coordinates of the cursor appears at the bottom of the screen.Repeatedly press

to see the value of the other graphed sequences at your specified value of T. Each time you press

the name of the sequence being evaluated appears at the top of the screen and the coordinates of the cursor location appear at the bottom of the screen.

**Web format:**In this format, the specified value of*n*and the coordinates of the cursor appear at the bottom of the screen. The*y*-coordinate is the value of the sequence at the specified value of*n*.*

**uv, vw, and uw format:**In this format, the specified value of*n*and values for*x*and*y*appear at the bottom of the screen. If you are in**uv**format,*x*is the value of*u*(*n*) and*y*is the value of*v*(*n*). In**vw**format,*x = v*(*n*) and*y*=*w*(*n*), and so on.

After using the

**value**command to evaluate your sequence at one value of*n*, you can evaluate your sequence at another value of*n*by simply keying in the new value of*n*and then pressing**[ENTER]**. Pressing any function key (such as**[ENTER]**or**[TRACE]**)*after*evaluating a function will deactivate the**value**command.

If you’re planning on evaluating sequences at several specified values of *n*, consider constructing a user-defined table.