Exercise · ZW-RECURRENCE-RELATION-003 · ★☆☆ Basic
Let \(a_0=1\) and \(a_n=a_{n-1}+2n\). What is \(a_5\)?
Choose one option.
Show answer
- A. 31
Explanation
\(a_1=3,\ a_2=7,\ a_3=13,\ a_4=21,\ a_5=21+10=31\).
Review the concept: Recurrence relation
A recurrence relation is an equation that expresses each term \(a_n\) of a sequence in terms of the previous \(k\) terms; with initial values, it determines the whole sequence.
\[a_n=f(a_{n-1},a_{n-2},\dots,a_{n-k})\]
More practice problems: recurrence relation
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