If , prove that the points (a, a2), (b,b2),(c, c2) can never be collinear.
Area of the triangle having vertices (x1,y1), (x2,y2) and (x3,y3)
= |x1(y2-y3)+x2(y3-y1)+x3(y1-y2)|
∴ Area = | a (b2 - c2) + b( c2 - a2) + c(a2 – b2)|
= | ab2 - ac2 + bc2 - ba2 + ca2 – cb2|
= | (b – c)(- a2 ) + ab +ac –bc|
= | (b – c)(a - b)(c – a)|
Also it is given that .
Hence area of triangle made by these points is never zero. Hence given points are never collinear.