Coordinate Geometry Question 168

Question: Orthocentre of the triangle whose vertices are (0, 0) (2, -1) and (1, 3) is

[ISM Dhanbad1970; IIT 1967, 74]

Options:

A) $ ( \frac{4}{7},\frac{1}{7} ) $

B) $ ( -\frac{4}{7},-\frac{1}{7} ) $

C) (-4, -1)

D) (4, 1)

Show Answer

Answer:

Correct Answer: B

Solution:

Equation of line BC is $ 4x+y=7 $ , then equation of line AD is $ x-4y+k=0 $ but it passes through (0,0) hence $ k=0 $ thus equation of $ AD=x-4y=0 $ …..(i) Similarly the equation of $ AC=3x-y=0 $ and BE is $ x+3y+1=0 $ …..(ii)

On solving (i) and (ii), the required orthocentre is $ ( \frac{-4}{7},\frac{-1}{7} ) $ .