The line segment joining the points A (3, 2) and B (5,1) is divided at the point P in the ratio 1:2 and it lies on the line 3x – 18y + k = 0. Find the value of k.
Solution:
Here points A(3, 2) and B(5, 1) is divided at the point P in the ratio 1 : 2
(x1, y1) = (3, 2) (x2, y2) = (5, 1)
m1 = 1, m2 = 2
By section formula we have
Line is 3x – 18y + k = 0 ......(1)
11 – 30 + k = 0
–19 + k = 0
k = 19