## Numerical Integration

Press
to access the numerical integration option
which approximates the definite integral
of an expression with respect to a variable from a start value to an end value.

Next, enter an expression, the variable, a start value, and an end value
separated by commas. For example, to find the antiderivative of x^{3}
evaluated from x = 1 to x = 2, enter

3
1 2

**Note:** The value of tolerance, `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?.