The radius of the circle x² + y² + 2x + 4y + 1 = 0 is?
Question 1
Q1. The radius of the circle x² + y² + 2x + 4y + 1 = 0 is?
Answer: 2
Explanation: Rewrite the equation as (x+1)² + (y+2)² = 4 by completing the square. So, radius = √4 = 2.