Solution 10419: Correcting ERROR 20 GRAPH WINDOW on the TI-86.
How can I correct ERROR 20 GRAPH WINDOW on the TI-86?
The ERROR 20 GRAPH WINDOW occurs when the minimum value for x or y is larger than the maximum value.
Edit the window values to resolve this error:
1) Press [GRAPH] [F2] and input the following values:
xMin = -10
xMax = 10
xScl = 1
yMin = -10
yMax = 10
yScl = 1
xRes = 1
An alternate method may be used by pressing [GRAPH] [F3] and selecting [F4] to reset the values to the Zoom Standard. A standard viewing window should be shown.