Create your own arithmetic sequence. List at least six terms of your sequence. Explain what makes it arithmetic.

State the fifth term of your arithmetic sequence using subscript notation.
Write an explicit formula for your arithmetic sequence. Use your explicit formula to find the 100th term of your sequence.
Write a recursive formula to represent your arithmetic sequence, make sure you identify the first term
Graph your arithmetic sequence using coordinate points

1 answer

Sure! Let's create an arithmetic sequence.

Creating an Arithmetic Sequence

Let's define our arithmetic sequence as follows:

  • First Term (a₁): 2
  • Common Difference (d): 3

Listing the First Six Terms

Using the first term and the common difference, the sequence is:

  1. \( a_1 = 2 \)
  2. \( a_2 = a_1 + d = 2 + 3 = 5 \)
  3. \( a_3 = a_2 + d = 5 + 3 = 8 \)
  4. \( a_4 = a_3 + d = 8 + 3 = 11 \)
  5. \( a_5 = a_4 + d = 11 + 3 = 14 \)
  6. \( a_6 = a_5 + d = 14 + 3 = 17 \)

So our sequence is: 2, 5, 8, 11, 14, 17

Explanation of Arithmetic Sequence

An arithmetic sequence is defined by a constant difference between consecutive terms. In this sequence, the common difference \(d\) is 3. This means that each term is derived by adding 3 to the previous term.

Fifth Term in Subscript Notation

The fifth term of our arithmetic sequence is denoted as: \[ a_5 = 14 \]

Explicit Formula

The explicit formula for an arithmetic sequence can be written as:

\[ a_n = a_1 + (n - 1)d \]

Substituting in our values: \[ a_n = 2 + (n - 1) \cdot 3 \]

This simplifies to: \[ a_n = 3n - 1 \]

Finding the 100th Term

To find the 100th term \(a_{100}\): \[ a_{100} = 3(100) - 1 = 300 - 1 = 299 \]

Recursive Formula

The recursive formula for our arithmetic sequence will be as follows:

  1. Initial Value: \( a_1 = 2 \)
  2. Recursive Step: \( a_n = a_{n-1} + 3 \) for \( n \geq 2 \)

Graphing the Sequence

To graph the arithmetic sequence, we plot the points corresponding to each term:

  • \( (1, 2) \)
  • \( (2, 5) \)
  • \( (3, 8) \)
  • \( (4, 11) \)
  • \( (5, 14) \)
  • \( (6, 17) \)
  • And so forth...

Here's a rough representation (not to scale):

  Y
  |
17|           * (6, 17)
14|        * (5, 14)
11|     * (4, 11)
 8|  * (3, 8)
 5|* (2, 5)
 2|* (1, 2)
  |_________________ X
     1  2  3  4  5  6

This graph demonstrates the linear growth of the terms as we move along the x-axis. Each point signifies a term in the arithmetic sequence, and they form a straight line due to the constant difference between successive terms.