1) If the points (a,0) (0,b) and (1,1) are collinear then show that 1/a+1/b=1
Area of triangle whose vertices are (x1, y1), (x2, y2) and (x3, y3) .
Suppose the given point be A(a, 0), B(0, b) and C(1, 1).
The given points are collinear.
∴ Area of ΔABC = 0
Thus, the given points are collinear if .