Lesson: Using Arithmetic Sequence Formulas Mathematics • 9th Grade

In this lesson, we will learn how to write explicit and recursive formulas for arithmetic sequences to find the value of the 𝑛th term in an arithmetic sequence and how to find a term’s order given its value.

Lesson Plan

Students will be able to

calculate a specified term of an arithmetic sequence using the relation ,
find the number of terms in a given arithmetic sequence,
calculate the formula for the term of an arithmetic sequence,
find the order of a specific term in an arithmetic sequence.

Lesson Presentation

Lesson Video

Lesson Explainer

Lesson Worksheet

Q1:

Fill in the blank: If the first term of an arithmetic sequence equals 16 and , then the fifth term equals .

Q2:

Find, in terms of , the general term of the arithmetic sequence .

Q3:

Using the table, determine the expression that represents the value of each term as a function of its position. Then, find the value of the eighteenth term in the sequence.

Position	6	7	8	9
Value of Term	19	22	25	28