NTA Abhyas JEE Main2020MathematicsStraight LinesPractice
Let orthocentre of Δ A B C is 4,6 . If A = 4,7 and B = - 2,4 , then coordinates of vertex C is
Options
- A5,4
- B4,5
- C- 5 , - 4
- D- 4 , - 5
Correct answer
A. 5,4
Step-by-step solution
Let feet of altitudes through A , B , C are D , E , F respectively. Now, C lies on the line C F , C A & C B Now, the slope of A D is 7 - 6 4 - 4 = N . D . ⇒ the slope of B C is 0 ⇒ equation of B C is y = 4 Now, the slope of B E is 6 - 4 4 - ( - 2 ) = 1 3 ⇒ the slope of A C is - 3 ⇒ equation of the line A C is y - 7 = - 3 x - 4 Point of intersection of y = 4 and y - 7 = - 3 x - 4 gives point C ⇒ C = 5 , 4