Solution 10449: Using the Interpolate Editor on the TI-85 and TI-86.
How do I use the interpolate editor on the TI-85 or TI-86?
The following instructions demonstrate how to use the interpolate/extrapolate feature of the TI-85 and TI-86.
Example: Given points (3,6) and (-1,-2), find the y value at x=7.
• Press [2nd] [MATH] [MORE] [F1] to enter the editor.
• At x1=, input 3 and press [ENTER].
• At y1=, input 6 and press [ENTER].
• At x2=, input -1 and press [ENTER].
• At y2=, input -2 and press [ENTER].
• At x=, input 7 and press [ENTER].
• At y=, press [F5] to solve for the y value. The calculator should display 14 as the solution.
Please see the TI-85 and TI-86 guidebooks for additional information.