Math Problem Statement

Given the sequence representation below, complete the recursive and explicit equations.

Solution

In the image, you have a question related to sequence representations that involves plotting points on a graph, and you are required to find both the recursive equation and the explicit equation of the sequence.

Step-by-step approach:

1. Analyzing the Points

The points on the graph appear to be at:

  • (0,5)(0, 5)
  • (1,3)(1, 3)
  • (2,1)(2, 1)
  • (3,1)(3, -1)

These points suggest that the sequence is linear, as the differences between successive points on the y-axis are constant.

2. Finding the Recursive Equation

A recursive formula expresses each term in the sequence in relation to the previous term.

  • The first term a1a_1 is the value of the sequence at x=0x = 0, which is a1=5a_1 = 5.
  • The common difference (the difference between successive terms) is 35=23 - 5 = -2.

So, the recursive equation will be: an=an12witha1=5a_n = a_{n-1} - 2 \quad \text{with} \quad a_1 = 5

3. Finding the Explicit Equation

To write the explicit equation, we use the form of the equation for an arithmetic sequence: an=a1+(n1)da_n = a_1 + (n-1) \cdot d where a1a_1 is the first term and dd is the common difference.

Substituting a1=5a_1 = 5 and d=2d = -2: an=5+(n1)(2)a_n = 5 + (n-1) \cdot (-2) Simplifying: an=52(n1)a_n = 5 - 2(n-1) an=52n+2a_n = 5 - 2n + 2 an=72na_n = 7 - 2n

Thus, the explicit equation is: an=72na_n = 7 - 2n

Conclusion:

  • Recursive equation: an=an12a_n = a_{n-1} - 2 with a1=5a_1 = 5
  • Explicit equation: an=72na_n = 7 - 2n

Would you like further clarification on any step?


Here are some related questions to explore further:

  1. What is the significance of a recursive equation in sequences?
  2. How can you determine if a sequence is arithmetic from a graph?
  3. Can a sequence have both recursive and explicit representations?
  4. What are some real-life applications of arithmetic sequences?
  5. How would the equations change if the common difference were positive?

Tip: When analyzing sequences, always check if the differences between terms are consistent to identify arithmetic sequences.

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Math Problem Analysis

Mathematical Concepts

Arithmetic Sequences
Linear Equations

Formulas

Recursive formula: a_n = a_{n-1} + d
Explicit formula: a_n = a_1 + (n-1) * d

Theorems

Arithmetic sequence formula

Suitable Grade Level

Grades 8-10