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1.1 Proof by Contradiction

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Question 45
i.

A digital signal processor generates a sequence of values based on prime numbers. Prove that for all prime numbers, ppp, such that 5≤p≤135 \le p \le 135≤p≤13,

p2−1 is a multiple of 24 p^2 - 1 \text{ is a multiple of } 24 p2−1 is a multiple of 24
[3]
ii.

Use proof by contradiction to show that for any positive integer nnn,

n2+2 is not a multiple of 4 n^2 + 2 \text{ is not a multiple of } 4 n2+2 is not a multiple of 4
[4]
Markscheme

1.1 Proof by Contradiction Questions

  1. A Level
  2. /Maths
  3. /1.1 Proof by Contradiction

107 exam-style questions on Edexcel A Level Maths 1.1 Proof by Contradiction. Each one has a worked solution and a mark scheme showing where the marks go.

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