Arithmetic and geometric sequences

Recommended first: Domain and range from a graph. You can still continue here.

A sequence is a list that follows a rule. Two rules cover most of what you'll see. In an arithmetic sequence, you add the same number each time. In a geometric one, you multiply by the same number.

Why $n-1$? To reach the 5th term from the 1st, you take 4 steps, not 5.

Work through it

Watch out for this

Using $n$ steps rather than $n-1$.

The first term already takes up position 1. Getting to term $n$ takes $n-1$ steps.

Your turn

Prefer paper? Print the Functions and sequences worksheet, with an answer key.

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