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0580/22 May/Jun 2022, Question 18: Proportion to Powers of x

Cambridge IGCSE Mathematics 0580 · Paper 22 (Extended) · Calculator · 4 marks

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The question, in short

Proportionality question: use the cube root relationship with x = 7, y = 1 to find y at x = 124, and describe the effect on F when d is halved.

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Part (a) · 3 marks

Given y proportional to cube root of (x + 1), with x = 7 giving y = 1, find y when x = 124.

  1. 1y = k × ∛(x + 1)
  2. 21 = k × ∛8 = 2k, so k = 1/2
  3. 3y = 1/2 × ∛(124 + 1) = 1/2 × 5
  4. 4y = 2.5

Answer2.5

Part (b) · 1 mark

F is inversely proportional to d squared; state how F changes when d is halved.

  1. 1F = k/d²; if d is halved, d² is divided by 4
  2. 2So F is multiplied by 4

Answermultiplied by 4

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Also searched as: 0580/22/M/J/22 · 0580_s22_qp_22 · 0580 s22 22 · question 18.
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