What to Exactly Put Into A Graphing Calculator for Sequences

Basic Sequence Input

To input a sequence into your graphing calculator, follow these steps:

1. Press the "LIST" or "SEQ" button to access the sequence editor.
2. Select "Edit..." to create a new sequence.
3. Enter the sequence formula in the format n, a(n), start, end where:
   • n is the variable (usually n)
   • a(n) is the formula for the nth term
   • start is the first term number
   • end is the last term number
4. For example, to enter the sequence 2, 5, 8, 11, enter n, 3n-1, 1, 4.

n, a(n), start, end

Recursive Sequences

For recursive sequences (where each term depends on previous terms), use the recursive editor:

1. Access the recursive sequence editor (often under "SEQ" or "LIST").
2. Enter the base case(s) first.
3. Enter the recursive formula using the previous term notation (e.g., u(n)=u(n-1)+3).
4. Specify the starting term number and how many terms to calculate.

Common Sequence Types

Here are examples of common sequence types and how to enter them:

Arithmetic Sequence

Formula: a(n) = a₁ + (n-1)d

Example: 3, 7, 11, 15 (d=4)

Enter: n, 3+4(n-1), 1, 4

Geometric Sequence

Formula: a(n) = a₁ * r^(n-1)

Example: 2, 6, 18, 54 (r=3)

Enter: n, 2*3^(n-1), 1, 4

Quadratic Sequence

Formula: a(n) = an² + bn + c

Example: 1, 4, 9, 16 (n²)

Enter: n, n^2, 1, 4

Graphing Tips

To graph a sequence effectively:

1. Enter the sequence in the sequence editor as shown above.
2. Go to the graph screen and select "PlotSeq" to display the sequence.
3. Adjust the window settings to show all terms clearly.
4. Use the "Dot" mode to see individual points or "Connected" mode to see the sequence as a line.

Troubleshooting

If your sequence isn't displaying correctly:

• Check that you've entered the formula correctly in the sequence editor.
• Verify that the start and end values are appropriate for your sequence.
• Ensure you've selected the sequence to plot in the graph screen.
• Adjust the window settings if the sequence appears cut off.