The equation x² + y² + 4x - 6y + 9 = 0 represents a circle. What is its radius?
Question 1
Q1. The equation x² + y² + 4x - 6y + 9 = 0 represents a circle. What is its radius?
Answer: 2
Explanation: Complete the square: (x+2)² + (y-3)² = 4. Radius = √4 = 2.