Question:

If the point \((2,\lambda)\) lies inside the circles \(x^2+y^2=13\) and \(x^2+y^2+x-2y=14\), then \(\lambda\) lies in the set:

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To check whether a point lies inside a circle, substitute the point in the circle equation and use the inequality form. For a circle \(S=0\), the inside region is generally obtained by comparing with the radius form or using the corresponding inequality.
Updated On: Jun 26, 2026
  • \((-\infty,-3)\cup(4,\infty)\)
  • \((-\infty,-1)\cup(3,\infty)\)
  • \([-3,4]\)
  • \([-2,3]\)
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The Correct Option is D

Solution and Explanation

Step 1: Use the condition for a point to lie inside the first circle.
The first circle is \[ x^2+y^2=13 \] For the point \((2,\lambda)\), we substitute \[ x=2,\quad y=\lambda \] For the point to lie inside or on the circle, \[ 2^2+\lambda^2\leq 13 \] \[ 4+\lambda^2\leq 13 \] \[ \lambda^2\leq 9 \] Hence, \[ -3\leq \lambda \leq 3 \]

Step 2: Use the condition for a point to lie inside the second circle.
The second circle is \[ x^2+y^2+x-2y=14 \] Substitute \[ x=2,\quad y=\lambda \] So, \[ 2^2+\lambda^2+2-2\lambda\leq 14 \] \[ 4+\lambda^2+2-2\lambda\leq 14 \] \[ \lambda^2-2\lambda+6\leq 14 \] \[ \lambda^2-2\lambda-8\leq 0 \] Factorizing, \[ (\lambda-4)(\lambda+2)\leq 0 \] Thus, \[ -2\leq \lambda \leq 4 \]

Step 3: Take the common interval.
From the first circle, \[ \lambda\in[-3,3] \] From the second circle, \[ \lambda\in[-2,4] \] Therefore, the common interval is \[ [-3,3]\cap[-2,4]=[-2,3] \]

Step 4: Final conclusion.
Hence, \[ \boxed{[-2,3]} \]
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