KCET2007MathematicsThree Dimensional Geometry
The coordinates of the foot of the perpendicular drawn from the point (3,4) on the line 2 x+y-7=0 is
Options
- A( 9 5 , 17 5 )
- B(1,5)
- C(-5,1)
- D(1,-5)
Correct answer
A. ( 9 5 , 17 5 )
Step-by-step solution
We know that foot of the perpendicular (h, k) from (x₁, y₁ ) to the line a x+b y+c=0 is given by h-x₁ a = k-y₁ b = - (a x₁+b y₁+c ) a²+b² Here, point (x₁, y₁ )=(3,4) and a x+b y+c=2 x+y-7=0 a=2, b=1, c=-7 then, from Eq. (i) h-3 2 = k-4 1 = -(2 3+1 4-7) 2²+1² h-3 2 = k-4 1 = -3 5 h= +9 5 and k= 17 5