Education Technology

Solution 12095: Finding Limits with Direction on the TI-89 Family, TI-92 Family, and Voyage™ 200 Graphing Calculators.

How do I find the limit with direction on the TI-89 family, TI-92 family, and Voyage 200 graphing calculators?

The example below will demonstrate how to input limits with direction on these calculators.

Example: Find the limit of x/(x-3) as x approaches 3 from the left, right, and both sides. To find the limit command, please press [F3:Caclulus] and select [3:limit(].

From the left:

limit(x/(x-3),x,3,-1) (-1 was arbitrarily chosen to specify the left direction. Any negative number can be used.)

The screen will show the - infinity symbol.

From the right:

limit(x/(x-3),x,3,1) (Choose any positive number.)

The screen will show the positive infinity symbol.

From both sides

limit(x/(x-3),x,3)

The screen will show undef.

Please see the TI-89 family, TI-92 family and Voyage 200 guidebooks for additional information.