(b) Since, orthocentre, centroid and circumcentre of a triangle are collinear whereas centroid divides orthocentre and circumcentre in the ratio of 2:1. By internally division formula
2p+1h
2+1
= g ⇒ 2p + h - 3g = 0 As, xp + yh + zg = 0 Hence, x = 2,y = 1 and z = -3