JEE Main 2019 Mathematics question
If a variable line, 3x + 4y − λ = 0 is such that the two circles and are on its opposite sides, then the set of all values of λ is the interval:
Answer: (D)
Solution
Centres (1, 1), r = 1 and (9, 1), r = 2 on opposite sides and not cut: 12 ≤ λ ≤ 21.