Determine the ratio in which the straight line x - y - 2 = 0 divides the line segment joining (3, -1) and (8, 9).
Let point be A(3, -1) and B(8, 9).
Let the line divide the line joining the points A and B in the ratio m:n at any point C(x, y)
By section formula,
x = , y =
For point C(x, y),
x = , y =
∴ x = , y =
Now, substituting value of x and y in equation x - y - 2 = 0,
-
-2 = 0
= 0
∴ -3m +2n =0
∴ =
∴ m:n = 2:3
Hence, the line divides the line segment joining A and B in the ratio 2:3 internally.