Edexcel Paper 1 2020 October — Question 10

Exam BoardEdexcel
ModulePaper 1 (Paper 1)
Year2020
SessionOctober
TopicIntegration by Substitution

  1. (a) Use the substitution \(x = u ^ { 2 } + 1\) to show that
$$\int _ { 5 } ^ { 10 } \frac { 3 \mathrm {~d} x } { ( x - 1 ) ( 3 + 2 \sqrt { x - 1 } ) } = \int _ { p } ^ { q } \frac { 6 \mathrm {~d} u } { u ( 3 + 2 u ) }$$ where \(p\) and \(q\) are positive constants to be found.
(b) Hence, using algebraic integration, show that $$\int _ { 5 } ^ { 10 } \frac { 3 \mathrm {~d} x } { ( x - 1 ) ( 3 + 2 \sqrt { x - 1 } ) } = \ln a$$ where \(a\) is a rational constant to be found.