Lemmara logoLemmaraWorked solution

4024/12 Oct/Nov 2024, Question 24: Perpendicular Lines

Cambridge O Level Mathematics 4024 · Paper 12 (Non-calculator) · Non-calculator · 5 marks

اقرأ هذا الحل مشروحاً بالعربي ←

The question, in short

Given points P(−1, 4) and Q(−3, −2), work out the midpoint of PQ and the equation of the line through P that is perpendicular to PQ.

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

Part (a) · 1 mark

Work out the coordinates of the point halfway between P(−1, 4) and Q(−3, −2).

  1. 1Midpoint = ((−1 + (−3))/2, (4 + (−2))/2) = (−2, 1)

Answer(−2, 1)

Part (b) · 4 marks

Work out the equation of the straight line that goes through P(−1, 4) and is at right angles to PQ.

  1. 1Gradient PQ = (−2 − 4)/(−3 − (−1)) = −6/−2 = 3
  2. 2Perpendicular gradient = −1/3
  3. 3Through P(−1, 4): 4 = −1/3 × (−1) + c, so c = 4 − 1/3 = 11/3
  4. 4y = −1/3 x + 11/3

Answery = −1/3 x + 11/3

Stuck on a step? Read the free lesson: Perpendicular Lines

Practise more perpendicular lines questions

Real 4024 past-paper questions, marked on your working like the exam, with a worked solution for every part.

Practise free on Lemmara

More past-paper questions on perpendicular lines

Also searched as: 4024/12/O/N/24 · 4024_w24_qp_12 · 4024 w24 12 · question 24.
Lemmara is an independent study tool, not affiliated with or endorsed by Cambridge International Education. The worked solutions are Lemmara’s own.