1.7.5 Geometric sequences and series (A-level only)

Consider the finite geometric series defined by the summation $∑i=0n−1ARi\sum_{i=0}^{n-1} A R^i$ .

Prove that the sum $S_n\,$ of this series is given by the formula

S_n = \frac{A(1 - R^n)}{1 - R}

[4]

Consider the finite geometric series defined by the summation $∑i=0n−1ARi\sum_{i=0}^{n-1} A R^i$ .

Prove that the sum $S_n\,$ of this series is given by the formula

S_n = \frac{A(1 - R^n)}{1 - R}

[4]

1.7.5 Geometric sequences and series (A-level only) Questions