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WMA11/01 Oct 2019, Question 2: Equation of a Line Through Two Points

Pearson Edexcel International AS Level Mathematics · Pure Mathematics 1 (WMA11) · Calculator · 5 marks

The question, in short

Tree height H metres t years after planting fits H = at + b, with H = 1.85 at t = 2 and H = 3.45 at t = 7. Find a and b, then the height at planting.

Summarised in our own words. Use the official paper for the exact wording and any diagrams.

Part (a) · 4 marks

Use the two given height-time pairs to form equations and solve for constants a and b in H = at + b.

  1. 11.85 = 2a + b and 3.45 = 7a + b
  2. 2Subtract: 5a = 1.6, so a = 0.32
  3. 3b = 1.85 − 2(0.32) = 1.21

Answera = 0.32, b = 1.21

Part (b) · 1 mark

Using the model with your values of a and b, state the tree height at t = 0.

  1. 1When planted, t = 0, so H = b
  2. 2H = 1.21 m

Answer1.21 m

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Also searched as: WMA11 October 2019 · WMA11/01 · wma11 oct19 · IAS Maths Pure Mathematics 1 October 2019 · question 2.
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