NTA Abhyas JEE Main2020MathematicsStraight LinesPractice
Let x 1 , y 1 ,   x 2 , y 2 ,   x 3 , y 3 and x 4 , y 4 are four points which are at unit distance from the lines 3 x - 4 y + 1 = 0 and 8 x + 6 y + 1 = 0 , then the value of ∑ i = 1 4 x i ∑ i = 1 4 y i is equal to
Options
- A2
- B– 2
- C1
- D– 1
Correct answer
B. – 2
Step-by-step solution
Point of intersection of lines 3 x - 4 y + 1 = 0 and 8 x + 6 y + 1 = 0 is - 1 5 , 1 10 Now, ∑ i = 1 4 x i = 4 - 1 5 = - 4 5 and ∑ i = 1 4 y i = 4 1 10 = 2 5 ⇒ ∑ i = 1 4 x i ∑ i = 1 4 y i = - 4 5 2 5 = - 2