A) \[14x+23y-40=0\]
B) \[14x-23y+40=0\]
C) \[23x+14y-40=0\]
D) \[23x-14y+40=0\]
Correct Answer: A
Solution :
Let\[B({{x}_{1}},{{y}_{1}})\]and\[C({{x}_{2}},{{y}_{2}})\]be two vertices and\[P\left( \frac{{{x}_{1}}+1}{2},\frac{{{y}_{1}}-2}{2} \right)\]lies on perpendicular bisector\[x-y+5=0\]. \[\therefore \] \[\frac{{{x}_{1}}+1}{2}-\frac{{{y}_{1}}-2}{2}=-5\] \[\Rightarrow \] \[{{x}_{1}}-{{y}_{1}}=-13\] ...(i) Also, PAT is perpendicular to AB. \[\therefore \] \[\frac{{{y}_{1}}+2}{{{x}_{1}}-1}\times 1=-1\] \[\Rightarrow \] \[{{y}_{1}}+2=-{{x}_{1}}+1\] \[\Rightarrow \] \[{{x}_{1}}+{{y}_{1}}=-1\] On solving Eqs. (i) and (ii), we get \[{{x}_{1}}=-7,{{y}_{1}}=6\] \[\therefore \]The coordinates of B are\[(-7,\text{ }6)\]. Similarly, the coordinates of C are\[\left( \frac{11}{5},\frac{2}{5} \right)\] Hence, the equation of BC is \[y-6=\frac{\frac{2}{5}-6}{\frac{11}{5}+7}\times (x+7)\] \[\Rightarrow \] \[(y-6)=\frac{-14}{23}\times (x+7)\] \[\Rightarrow \] \[14x+23y-40=0\]You need to login to perform this action.
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