What is the radius of the circle x² + y² - 10x + 8y + 25 = 0?
Question 1
Q1. What is the radius of the circle x² + y² - 10x + 8y + 25 = 0?
Answer: √(25 + 16 - 25) = 4
Explanation: Complete the square: (x-5)² + (y+4)² = 25 + 16 - 25 = 16 ⇒ Radius 4.