Lesson Plan

Write the explicit rule aₙ = a₁ + (n − 1)d for an arithmetic sequence and use it to find any term, and use Sₙ = (n/2)(a₁ + aₙ) to find the sum of the first n terms

Test whether a sequence is arithmetic by computing all consecutive differences, and state the common difference, including when it is negative

Write the recursive rule aₙ = aₙ₋₁ + d (with a₁ stated) and distinguish it from the explicit rule

Find d, a₁, or a missing term given any two terms, by counting the gaps between their positions

Identify an arithmetic sequence as a linear function of its index, with d as the slope

Solve ACT-style word problems that model a repeating fixed increase, distinguishing requests for a term from requests for a sum

F 201. Extend a given pattern by a few terms for patterns that have a constant increase or decrease between terms F 502. Find the next term in a sequence described recursively F 603. Find a recursive expression for the general term in a sequence described recursively A 406. Exhibit knowledge of slope A 514. Determine the slope of a line from an equation F 503. Build functions and use quantitative information to identify graphs for relations that are proportional or linear AF 503. Match linear equations with their graphs in the coordinate plane