Standard +0.3 This is a straightforward method of differences question where the telescoping form is already given. Students need only write out the first few and last few terms to identify what survives, then evaluate. While it requires careful bookkeeping and understanding of telescoping series, it's a standard technique with no conceptual obstacles or novel insight required.
1 In this question you must show detailed reasoning.
Find \(\sum _ { r = 1 } ^ { 100 } \left( \frac { 1 } { r } - \frac { 1 } { r + 2 } \right)\), giving your answer correct to 4 decimal places.
1 In this question you must show detailed reasoning.\\
Find $\sum _ { r = 1 } ^ { 100 } \left( \frac { 1 } { r } - \frac { 1 } { r + 2 } \right)$, giving your answer correct to 4 decimal places.
\hfill \mbox{\textit{OCR MEI Further Pure Core AS 2019 Q1 [3]}}