## Zero Option

The zero option is used to find an x intercept. While viewing a graph, press
.

Press .
(The zero option can also be obtained by using the
to select option 2 and pressing
.)

The question "Lower Bound?" appears at the bottom of the screen. Since a function may have more than one x intercept, specify an interval
containing the desired x intercept. The "3" in the upper right-hand corner
indicates finding an x intercept on the graph of the third function.
Use the to move the blinking cursor
to the *left* of one of the x intercepts. Press .

The question "Upper Bound?" appears at the bottom of the screen. Use the
to move the blinking cursor
to the right of the x intercept. Press .

The coordinates of the x intercept appear at the bottom of the screen. In this case
the x intercept is about -6.28.