Here's the quickest way to get the arc length. Press **MENU**,
then press **9** to access the CAS screen. From the CAS screen, press **F2**
to access the CALC menu. Press **7** to select item 7:arcLen. After arcLen(
is pasted in the entry line, type in the functional expression, the input variable,
left input value, right input value, close the parentheses and execute. For example,
we illustrate the arc length of *y* = *x** *^{2} from *x*
= -1 to *x* = 2. Here, enter the arcLen( item to read: arcLen(x^{2},x,-1,2),
then press **EXE**.

The exact answer is displayed. To get a decimal approximation to this formidable
answer, press **F1** to select TRNS menu, then select **B:approx**. In response
to the approx prompt in the entry line, press **SHIFT ANS
EXE**. A humane decimal approximation appears.