The radius of the director circle of the ellipse x²/a² + y²/b² = 1 is
Q1. The radius of the director circle of the ellipse x²/a² + y²/b² = 1 is
Answer: √(a² + b²)
Explanation: The director circle of an ellipse has the equation x² + y² = a² + b², hence its radius is √(a² + b²).