Solve Limit Problems on a Calculator Using Graphing Mode

To begin, enter the limit expression in graphing or “y =” mode, go to Table Setup, set Tblstart to the arrow-number, and set

to something small like 0.01 or 0.001. When you look at the table, you’ll often see the y values getting closer and closer to the limit answer as x homes in on the arrow-number. If it’s not clear what the y values are approaching, try a smaller increment for the

number. This method often gives you a good feel for what’s happening in a limit problem.

Practice questions

1. Evaluate
   
2. Use your calculator to determine
   

Answers and explanations

1. The answer is 7. Step 1. Enter
   
   in graphing or “y =” mode. Step 2. Go to Table Setup and set tblStart to the arrow-number, 6, and
   
   to 0.01. Step 3. Go to the Table and you’ll see the y values getting closer and closer to 7 as you scroll toward x = 6 from above and below 6. So, 7 is your answer.
2. The answer is 1. Enter the function in graphing mode like this:
   
   Then go to table setup and enter a small increment into
   
   (try 0.01 for this problem), and enter the arrow-number, 0, into tblStart. When you scroll through the table near x = 0, you’ll see the y values getting closer and closer to the round number 1. That’s your answer. This problem is not easy to do with algebra.