Question

If the point (0,0), (1,2) and (x,y) are collinear, then find the relationship between x and y.

Answer 1

if three points are colinear then area of traingle form by three points is zero,

area of ∆=1/2{0+1(y-0)+x(0-2)}
0= 1/2{y-2x}
y-2x=0

2x-y=0 (ans)

Answer 2

As the points are collinear they don't form a triangle so area of triangle is Zero

Therefore 0(2-x)+1(y-0)+x(0-2)=0

y=2x