Question 11(a)
[Maximum number: 4]
The coordinates of points A, B and C are (6, 4), ( p, 7 ) and (14, 18) respectively, where p is a constant. The line A B is perpendicular to the line B C.
Given that p<10, find the value of p.
CAIE A-Level Mathematics 1.3.2 Straight-Line Equation Forms
Practise finding gradients, midpoints and perpendicular bisectors and expressing straight lines in gradient-intercept, point-gradient or general linear form.
How this is tested
- calculate a midpoint and use the negative reciprocal gradient for a perpendicular bisector
- form y − y₁ = m(x − x₁) from a point and gradient before rearranging as required
- verify parallel or perpendicular lines using equal gradients or a gradient product of −1