1.

If the points A (1, 2), B (0, 0) and C (a, b) are collinear, then A. a = b  B. a = 2b C. 2a = b D. a = - b

Answer»

Let the points are;

A = (x1, y1) = (1, 2)

B = (x2, y2) = (0, 0)

C = (x3, y3) = (a, b)

∵ Area of ∆ABC= ∆ = 1/2

[x1(y2 – y3) + x2(y3 – y1) + x3(y1 – y2)]

∴ ∆ =1/2 [1(0 - b) + 0(b - 2) + a(2 - 0)]

⇒Δ=1/2 ( - b + 0 + 2a)=1/2(2a - b)

As, the points A (1, 2), B (0, 0) and C (a, b) are collinear, then area of ΔABC will be equals to the zero

Area of ΔABC = 0

⇒1/2 (2a - b)

→ 2a - b = 0

→ 2a = b

Hence, the required relation is 2a = b



Discussion

No Comment Found

Related InterviewSolutions