JEE Main2013MathematicsThree Dimensional GeometryActual
Let A(-3,2) and B(-2,1) be the vertices of a triangle ABC . If the centroid of this triangle lies on the line 3 x+4 y+2=0 , then the vertex C lies on the line :
Options
- A4 x+3 y+5=0
- B3 x+4 y+3=0
- C4 x+3 y+3=0
- D3 x+4 y+5=0
Correct answer
B. 3 x+4 y+3=0
Step-by-step solution
Let C = (x₁, y₁ ) A (-3,2) Centroid, E = ( x₁-5 3 , y₁+3 3 ) Since centroid lies on the line aligned & 3 x+4 y+2=0 & 3 ( x₁-5 3 )+4 ( y₁+3 3 )+2=0 aligned 3 x₁+4 y₁+3=0 Hence vertex (x₁, y₁ ) lies on the line 3 x+4 y+3=0