Question

A plane meets the coordinate axis at A ,B ,C such that the centroid of the triangle ABC is (p ,q ,r).show that the equation of the plane is x/p +y/q +z/r =3

Answer 1

Let the equation of the plane be



The plane meets the coordinate axes at A, B and C. Hence, we have A(a, 0, 0), B(0, b, 0) and C(0, 0, c).

Since centroid of ΔABC is (p, q, r),



Put in equation (1).



is the equation of the required plane.