## Zero Option

The zero option is used to find an x intercept. Press .

Press . (The zero option can also be obtained by using the  to select option 2 and pressing .) Since a function may have more than one x intercept, specify an interval containing the desired x intercept. (The equation in the upper left-hand corner indicates finding an x intercept on the graph of the second function.)

The question "Left Bound?" appears at the bottom of the screen. Use the  to move the blinking cursor to the left of one of the x intercepts. Press .

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

The arrows at the top of the screen indicate the boundaries between which the calculator will give the root. (The arrows must point toward each other and an x intercept must lie between them.) The question "Guess?" appears at the bottom of the screen. Locate the cursor between the established boundaries. Press .

The coordinates of the x intercept appear at the bottom of the screen. In this case the x intercept is about 9.02.

Note: For a specific example using the zero option, read Exercise 4 of the Skill Building Exercises in the Prologue of Precalculus: Making Connections .