OCR MEI Paper 1 2021 November — Question 4

Exam BoardOCR MEI
ModulePaper 1 (Paper 1)
Year2021
SessionNovember
TopicSequences and Series

4
  1. The first four terms of a sequence are \(2,3,0,3\) and the subsequent terms are given by \(\mathrm { a } _ { \mathrm { k } + 4 } = \mathrm { a } _ { \mathrm { k } }\).
    1. State what type of sequence this is.
    2. Find \(\sum _ { \mathrm { k } = 1 } ^ { 200 } \mathrm { a } _ { \mathrm { k } }\).
  2. A different sequence is given by \(\mathrm { u } _ { \mathrm { n } } = \mathrm { b } ^ { \mathrm { n } }\) where \(b\) is a constant and \(n \geqslant 1\).
    1. State the set of values of \(b\) for which this is a divergent sequence.
    2. In the case where \(b = \frac { 1 } { 3 }\), find the sum of all the terms in the sequence.