Complete question is;
Given a circle with (4. -3) and (2, 1) as the endpoints of the diameter. Write the equation of the circle.
Answer:
x² + y² - 6x + 2y + 5 = 0
Explanation:
The end points of the diameter are;
(4. -3) and (2, 1).
Thus, the centre coordinates will be the midpoint of the diameter endpoints.
Thus;
Centre coordinates = ((4 + 2)/2), ((-3 + 1)/2) = (3, -1)
Diameter;
d = √(1 - (-3))² + (2 - 4)²)
d = √20
d = 2√5
Radius = ½ × diameter
Thus;
r = ½ × 2√5
r = √5
Equation of a circle is;
(x - a)² + (y - b)² = r²
Where;
(a, b) are coordinates of the centre of the circle
r is radius.
Thus;
(x - 3)² + (y - (-1))² = (√5)²
x² - 6x + 9 + y² + 2y + 1 = 5
x² + y² - 6x + 2y + 10 = 5
x² + y² - 6x + 2y + 10 - 5 = 0
x² + y² - 6x + 2y + 5 = 0