Question
Question: lines x + 2y – 1 = 0, ax + y + 3 = 0 and bx – y + 2 = 0 are concurrent and let S be the curve denoti...
lines x + 2y – 1 = 0, ax + y + 3 = 0 and bx – y + 2 = 0 are concurrent and let S be the curve denoting locus of (a, b). Then the least distance of S from the origin is.
A
575
B
515
C
585
D
595
Answer
585
Explanation
Solution
lines are concurrent
= 0
Ž 7b – 3a + 5 = 0
locus of (a, b) is 3x – 7y = 5
least distance from (0, 0) = length of perpendicular from (0, 0) =585