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Sequences & Series

Arithmetic and geometric sequences: nth term, sum of n terms, sum to infinity, or find a, d or r from two terms. Exact fractions throughout.

u=
u=
Fractions and decimals work, e.g. 1/2 or -0.5. The last two boxes are optional.

Working

Key facts

    First terms (dots: uₙ, line: Sₙ)

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