Let \[A\left( {2, - 3} \right)\] and \[B\left( {-2, 1} \right)\] be vertices of a triangle ABC. If the centroid of this triangle moves on the line 2x+3y=1, then the locus of the vertex C is the line :
Solutions · 1
Official solution
Let the vertex C be (h,k), then the
centroid of \[\Delta ABC\] is \[\left( {{{2 + (- 2) + h} \over 3},{{ - 3 + 1 + k} \over 3}} \right)\]
or \[\left( {{h \over 3},{{ - 2 + k} \over 3}} \right).\] It lies on 2x+3y=1
\[ \Rightarrow {{2h} \over 3} - 2 + k = 1\]
\[ \Rightarrow 2h + 3k = 9\]
\[ \therefore \] Locus of C is 2x+3y=9