Easy -1.2 This is a straightforward pattern recognition question requiring students to identify that the sequence alternates between a and -a, then recognize that 95 terms (odd number) gives a sum of a. It's a multiple-choice question testing basic understanding of alternating sequences with minimal calculation required—easier than average A-level content.
3 A sequence is defined by
$$u _ { 1 } = a \text { and } u _ { n + 1 } = - 1 \times u _ { n }$$
Find \(\sum _ { n = 1 } ^ { 95 } u _ { n }\)
Circle your answer.
\(- a\)
0
\(a\)
95a
3 A sequence is defined by
$$u _ { 1 } = a \text { and } u _ { n + 1 } = - 1 \times u _ { n }$$
Find $\sum _ { n = 1 } ^ { 95 } u _ { n }$\\
Circle your answer.\\
$- a$\\
0\\
$a$\\
95a
\hfill \mbox{\textit{AQA Paper 2 2021 Q3 [1]}}