10th Class Mathematics Coordinate Geometry Question Bank MCQs - Coordinate Geometry

If \[P(-1,1)\] is the mid-point of the line segment joining \[A(-3,b)\] and \[B(1,b+4)\] then b =

A) \[1\]

B) \[-1\]

C) \[2\]

D) \[0\]

Correct Answer: B

Solution :

[b] Since\[P(-1,1)\] is the mid-point of line segment joining \[A(-3,6)\] and \[B(1,6+4)\]

\[\therefore \,\,\,\,(-1,1)=\left( \frac{-3+1}{2},\frac{b+b+4}{2} \right)\,\Rightarrow \,\,b+2=1\Rightarrow b=-1\]