SQA Advanced Higher Mathematics specimen paper No. 16 Sum of a Series

Prove a given result for the sum of a series given as a summation of the general term. Find the value of n given conditions involving the sum. Instructional exercise consisting of question 16 from the SQA Advanced Higher Mathematics specimen paper produced in 2015. Where appropriate the alternative methods for solving the problem are also given. Set out in stages of 'try then check' the worked solution to each part of the question. Including indications of where each mark is allocated, and the requirements for that mark, according to the marking scheme.