Press to view the calculus menu, then to select numerical integration.

The syntax is: `fnInt( `

*expression*`,`

*variable*
`,`

*startValue*`,`

*endValue* ).

The numerical integration option approximates the definite integral of *expression*
with respect to *variable* from *startValue* to *endValue*.

`tol`

is used to determine how accurate to calculate
the 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
,
typically about 0.001.For more specific information and tips see Integration on the TI-how does it work?.