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1.1 Proof

1.1 Proof

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Question 62

Detailed reasoning must be shown in this question.

A researcher studying fluid dynamics determines that for any two positive flow rates uuu and vvv in a bifurcated pipe, the 'effective velocity' VeV_eVe​ and the 'total sum' SSS are defined as:

Ve=u3+v3u2+v2andS=u+v V_e = \frac{u^3 + v^3}{u^2 + v^2} \quad \text{and} \quad S = u + v Ve​=u2+v2u3+v3​andS=u+v
a.

Use proof by contradiction to show that Ve<SV_e < SVe​<S for all positive real numbers uuu and vvv.

[4]
b.

By providing a counter-example, show that the statement in part (a) is not true for all real numbers uuu and vvv where u2+v2≠0u^2 + v^2 \neq 0u2+v2=0.

[2]
Markscheme

1.1 Proof Questions

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

132 exam-style questions on OCR (MEI) A Level Maths 1.1 Proof, covering 1.1.1 Structure of mathematical proof, 1.1.2 Disproof by counter example, 1.1.3 Proof by contradiction (A-level only), and 1.1 Proof. Each one has a worked solution and a mark scheme showing where the marks go.

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