A geometric series is a+ar+ar2+…a + ar + ar^2 + \dotsa+ar+ar2+…
Prove that the sum of the first n n\,n terms of the series is
Sn=a(1−rn)1−r S_n = \frac{a(1-r^n)}{1-r} Sn=1−ra(1−rn)Practise Edexcel A Level Maths 3.4 Geometric Series with exam-style questions for A Level Maths. 27 questions, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.