4024/21 Oct/Nov 2025, Question 16: Equation of a line
Cambridge O Level Mathematics 4024 · Paper 21 (Calculator) · Calculator · 4 marks
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The question, in short
A is (3, −2) and B is (5, 4). Find the equation of line AB as y = mx + c, then give the gradient of a line perpendicular to AB.
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Part (a) · 3 marks
Find the equation of AB.
- 1Gradient = (4 − (−2))/(5 − 3) = 6/2 = 3
- 2y = 3x + c through (3, −2): −2 = 9 + c, c = −11
- 3y = 3x − 11
Answery = 3x − 11
Part (b) · 1 mark
Gradient of a perpendicular line.
- 1Perpendicular gradient = −1 ÷ 3 = −1/3
Answer−1/3
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Also searched as: 4024/21/O/N/25 · 4024_w25_qp_21 · 4024 w25 21 · question 16.
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