1.6.15 Standard formulae for geometric series (A-level only)

A geometric series is $ar^2 + \dots$

Prove that the sum of the first $n\,$ terms of the series is

S_n = \frac{a(1-r^n)}{1-r}

[4]

A geometric series is $ar^2 + \dots$

Prove that the sum of the first $n\,$ terms of the series is

S_n = \frac{a(1-r^n)}{1-r}

[4]

1.6.15 Standard formulae for geometric series (A-level only) Questions