Education Technology

Solution 34603: Finding the x-Intercept of a Function Using the TI-84 Plus C Silver Edition.

How can I find the x-intercepts of a function using the TI-84 Plus C Silver Edition?

To find the x-intercepts of a function using the TI-84 Plus C Silver Edition, the zero command must be used. Follow the example below for help with using the zero command.

Example function: 2X - 7

1) Press [Y=] to access the Y= Editor.
2) For Y1=, input the example function. Press [GRAPH] to graph the function.





3) To use the zero command, press [2nd] [TRACE] to access the CALC menu, then press [2] to select the zero command.
4) The handheld will then prompt for a "Left Bound". This means the handheld wants the user to select a point on the graph that is to the left of the x-intercept. Using the arrow keys, move the cursor until it is to the left of the x-intercept. Press [ENTER] to mark this as the left bound.



5) The handheld will then prompt for a "Right Bound". This means the handheld wants the user to select a point on the graph that is to the right of the x-intercept. Using the arrow keys, move the cursor until it is to the right of the x-intercept. Press [ENTER] to mark this as the right bound.



6) The handheld will then prompt for a "Guess". This means the handheld wants the user to take a guess at the x-intercept. Using the arrow keys, move the cursor until it is close to or directly on the x-intercept. Press [ENTER] to mark this as the guess. This will also complete the zero command and display the exact point of the x-intercept which is (3.5,0).





Please see the TI-84 Plus C Silver Edition guidebook for additional information.