WJEC Further Unit 1 2024 June — Question 5 7 marks

Exam BoardWJEC
ModuleFurther Unit 1 (Further Unit 1)
Year2024
SessionJune
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicSequences and series, recurrence and convergence
TypeFinding n for given sum value
DifficultyStandard +0.8 This requires manipulating a summation formula to form a quadratic equation in k, then solving it. Students must recognize how to split the sum, apply standard formulas for Σr and Σ1, and handle the algebra carefully with the variable lower limit. More challenging than routine series questions but not requiring deep insight—primarily algebraic manipulation with summation formulas.
Spec4.04h Shortest distances: between parallel lines and between skew lines4.06a Summation formulae: sum of r, r^2, r^3

5. Given that $$\sum _ { r = k } ^ { 76 } ( r - 31 ) = 980$$ show that there are two possible values of \(k\).
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Question 5:
AnswerMarks
57
Question 5:
5 | 7
5. Given that

$$\sum _ { r = k } ^ { 76 } ( r - 31 ) = 980$$

show that there are two possible values of $k$.\\

\section*{PLEASE DO NOT WRITE ON THIS PAGE}

\hfill \mbox{\textit{WJEC Further Unit 1 2024 Q5 [7]}}