A line perpendicular to the line segment joining the points (1, 0) and (2, 3) divides it in the ratio 1: n. Find the equation of the line.
We know that the coordinates of a point dividing the line segment joining the points (x1, y1) and (x2, y2) internally in the ratio m: n are .
∴
We know that slope, m =
∴ m =
We know that two non-vertical lines are perpendicular to each other if and only if their slopes are negative reciprocals of each other.
∴ m = (-1/m) =
We know that the point (x, y) lies on the line with slope m through the fixed point (x0, y0), if and only if, its coordinates satisfy the equation y – y0 = m (x – x0)
Here, the point is.
∴
⇒ 3((1 + n) y – 3) = (-(1 + n) x + 2 + n)
⇒ 3(1 + n) y – 9 = - (1 + n) x + 2 + n
⇒ (1 + n) x + 3(1 + n) y – n – 9 – 2 = 0
⇒ (1 + n) x + 3(1 + n) y – n – 11 = 0
Ans. The equation of the line is (1 + n) x + 3(1 + n) y – n – 11 = 0.