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1.1.3 Proof by contradiction (A-level only)

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Question 51

A cybersecurity researcher is analyzing a specific encryption key property. They need to prove that the equation p2−4q=2p^2 - 4q = 2p2−4q=2 has no integer solutions for ppp and qqq.

The researcher starts a proof by contradiction as shown below:

"Suppose there exist integers ppp and qqq such that p2−4q=2p^2 - 4q = 2p2−4q=2. This implies that

p2=4q+2 p^2 = 4q + 2 p2=4q+2

so p2p^2p2 is even."

Complete the proof.

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1.1.3 Proof by contradiction (A-level only) Questions

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