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(x2,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.