Answer:
13. x² + (y - 13)² = 4
14. (x + 1)² + (y + 12)² = 5
15. (x + 1)² + (y + 13)² = 9
Explanation:
13. x^2 + y^2 - 26y + 165= 0
h = 0/-2 = 0
k = -26/-2 = 13
0² + 13² - 165 = r²
r² = 4
r = 2
(x - 0)² + (y - 13)² = 2²
x² + (y - 13)² = 4
14. x^2 + y^2 + 2x + 24y + 140 = 0
h = 2/-2 = -1
k = 24/-2 = -12
(-1)² + (-12)² - 140 = r²
r² = 5
(x - (-1))² + (y - (-12))² = 5
(x + 1)² + (y + 12)² = 5
15. Ends of a diameter: (-1, -16) and (-1, -10)
Centre: midpoint of the diameter
(h,k) = (-1-1)/2, (-16-10)/2
= (-1,-13)
Diameter lebgrh= 16 - 10 = 6
Radius = 6/2 = 3
(x - (-1))² + (y - (-13))²= 3²
(x + 1)² + (y + 13)² = 9