JEE Main 2019 Mathematics question
If the circles and , (K ∈ R), intersect at the points P and Q, then the line 4x + 5y − K = 0 passes through P and Q, for:
Answer: (B)
Solution
Common chord ; matching with 4x + 5y − K = 0 needs K = 1/10 and K = −5/11 simultaneously — impossible.