to view the calculus menu, then
to select arc length.
The syntax is: arc( expression,variable
,startValue,endValue )
The maximum option finds the length along the curve expression as variable ranges from startValue to endValue.

.
The error is described as tolerance, tol. The value of tol is used to determine how accurate to calculate
this integral. The TI tries to keep the absolute error under tol.
A smaller value yields a more accurate integral but takes longer to compute.
It can be changed in the tolerance editor available by pressing
. Its
value is typically about 0.001.