Question

if points (a,0)(0,b)(1,1) are collinear then find the value of 1/a+1/b

Answer 1

as the points are collinear its area is 0.
here area=(1÷2){a(b-1)+0(1-0)+1(0-b)}
i.e. 0=ab-a-b
ab=a+b
1=(a+b)÷ab
1=1/a+1/b