Question:medium

The locus of point of intersection of the tangents to the circle \( x^2 + y^2 = 16 \), such that the angle between them is 60°, is

Show Hint

For a circle with center at the origin, the formula for the angle between two tangents can be used to find the locus of the intersection points.
Updated On: Jun 30, 2026
  • \( x^2 + y^2 = 4 \)
  • \( x^2 + y^2 = 64 \)
  • \( x^2 + y^2 = 32 \)
  • \( x^2 + y^2 = 48 \)
Show Solution

The Correct Option is C

Solution and Explanation

Step 1: Understanding the Question:
The tangents are drawn from an external point to a circle. The locus will be a concentric circle. We need to find its radius.
Step 2: Key Formula or Approach:
Let the external point be \( P(h, k) \). If \( \theta \) is the angle between tangents, then \( \sin(\theta/2) = \frac{r}{\text{OP}} \), where \( r \) is the radius of the circle and \( \text{OP} \) is the distance from center to \( P \).
Step 3: Detailed Explanation:
Given circle: \( x^2 + y^2 = 4^2 \Rightarrow r = 4 \). Center \( O = (0, 0) \).
Angle \( \theta = 60^\circ \Rightarrow \theta/2 = 30^\circ \).
\[ \sin 30^\circ = \frac{4}{\sqrt{h^2 + k^2}} \] \[ \frac{1}{2} = \frac{4}{\sqrt{h^2 + k^2}} \] \[ \sqrt{h^2 + k^2} = 8 \Rightarrow h^2 + k^2 = 64 \] Replacing \( (h, k) \) with \( (x, y) \), the locus is \( x^2 + y^2 = 64 \).
Step 4: Final Answer:
The locus is \( x^2 + y^2 = 64 \).
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