Math Problem Statement

An arithmetic sequence is given below.

3

,  

10

,  

17

,  

24

,  

...

Write an explicit formula for the 

nth

 term 

an

.

=an

Solution

To find the explicit formula for the nth term of an arithmetic sequence, we use the general form:

an=a1+(n1)da_n = a_1 + (n - 1) \cdot d

Where:

  • a1a_1 is the first term,
  • dd is the common difference between consecutive terms,
  • nn is the term number.

For the given sequence: 3, 10, 17, 24, ...

  • The first term a1=3a_1 = 3,
  • The common difference d=103=7d = 10 - 3 = 7.

Now, substitute these values into the formula:

an=3+(n1)7a_n = 3 + (n - 1) \cdot 7

Simplify the expression:

an=3+7n7a_n = 3 + 7n - 7 an=7n4a_n = 7n - 4

Thus, the explicit formula for the nth term is:

an=7n4a_n = 7n - 4

Would you like more details on how to derive the formula, or do you have any questions?


Here are 5 related questions to explore further:

  1. How do you find the common difference in an arithmetic sequence?
  2. What is the formula for the sum of the first n terms in an arithmetic sequence?
  3. How does an arithmetic sequence differ from a geometric sequence?
  4. What happens if the common difference is negative in an arithmetic sequence?
  5. Can you find the 10th term using the explicit formula?

Tip: Always verify the formula by checking if it gives the correct result for a few terms from the sequence.

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Math Problem Analysis

Mathematical Concepts

Arithmetic Sequences
Algebra

Formulas

an = a1 + (n - 1) * d

Theorems

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Suitable Grade Level

Grades 6-8