Options:
A) $ (-6,5) $
B) $ (5,6) $
C) $ (-5,6) $
D) $ (6,5) $
  Show Answer
  Answer:
Correct Answer: B
Solution:
- Equation of perpendicular on the line  $ x+y-11=0 $  is  $ x-y+\lambda =0 $ , but it passes through (2, 3), so  $ \lambda =1 $ .     Equation of perpendicular is  $ x-y+1=0 $ . Now the coordinates of the foot of the perpendicular are the intersection point of the lines, hence point is (5, 6).Aliter : Apply the formula given in the theory part of this book, we get required foot as   $ ( \frac{1^{2}\times 2-1\times 1\times 3-1\times (-11)}{1^{2}+1^{2}},\frac{1^{2}\times 3-1\times 1\times 2-1(-11)}{1^{2}+1^{2}} ) $       $ =( \frac{2-3+11}{2},\frac{3-2+11}{2} )=(5,6) $ .