OCR
Further Pure Core 1
2018
December
— Question 7
Exam Board
OCR
Module
Further Pure Core 1 (Further Pure Core 1)
Year
2018
Session
December
Topic
Sequences and series, recurrence and convergence
7
Determine an expression for \(\sum _ { r = 1 } ^ { n } \frac { 1 } { r ( r + 1 ) ( r + 2 ) }\) giving your answer in the form \(\frac { 1 } { 4 } - \frac { 1 } { 2 } \mathrm { f } ( n )\).
Find the value of \(\sum _ { r = 1 } ^ { \infty } \frac { 1 } { r ( r + 1 ) ( r + 2 ) }\).