Question

If the points a(2, 1), b(a, b) and c(4, 1) are collinear and a b = 1, find the values of a and b respectively.

Answer 1

here is your correct answer
area of triangle =

½[a1(b2-b3)+a2(b3-b1)+a3(b1-b2)

as points are collinear the area is zero here

a1=-2. b1=1

a2=a. b2=b

a3=4. b3=1

so putting value in eq

a=1 b=1