ExamBro
ExamBro
JEE Mains · Maths · STD 11 - 10.1 circle and system of circle

If a variable line, \(3x + 4y -\lambda  = 0\) is such that the two circles \(x^2 + y^2 -2x -2y + 1 = 0\) and \(x^2 + y^2 -18x -2y + 78 = 0\) are on its opposite sides, then the set of all values of \(\lambda \) is the interval

  1. A \((2, 17)\)
  2. B \([13, 23]\)
  3. C \([12, 21]\)
  4. D \((23, 31)\)
Verified Solution

Answer & Solution

Correct Answer

(C) \([12, 21]\)

Step-by-step Solution

Detailed explanation

\(3x + 4y - \lambda = 0\) \(\left( {7 - \lambda } \right)\left( {31 - \lambda } \right) < 0\) (since centres lie opposite side) \(\lambda \in \left( {7,13} \right)\,\,\,\,\,\,\,\,\,\,\,.......\left( 1 \right)\) \(\left| {\frac{{7 - \lambda }}{5}} \right| \ge 1\) and…
From JEE Mains
Explore more questions on app