Question:
<p>Suppose two perpendicular tangents can be drawn from the origin to the circle x<sup>2</sup> + y<sup>2</sup> - 6x - 2cy + 17 = 0, for some real c, then |c| is equal to :</p>
<p style="display:inline">5</p>
<p style="display:inline">17</p>
<p style="display:inline">0</p>
<p style="display:inline">3</p>
Step-by-Step Solution
Key Concept: The locus of points from which perpendicular tangents can be drawn to a circle is the director circle, which is concentric with the original circle and has a radius squared equal to $2r^2$.
<p>5</p>
Correct Answer: A