Asked by Anonymous
The equation of a circle is x^2 + 6x + y^2 - 2y = 15. What are the center and radius of the circle? Please show work.
Answers
Answered by
Anonymous
Complete the squares for x and y to put into standard (x - h)^2 + (y - k)^2 = r^2
for center (h , k) and rdius r
x^2 + 6x + y^2 - 2y = 15
x^2 + 6x + 9 + y^2 - 2y + 1 = 15 + 9 + 1 = 25
(x + 3)^2 + (y - 1)^2 = 25
comparing to the standard form:
center (h , k) is (-3 , 1)
r^2 = 25 > radius r = 5
Center (-3,1)
xc= -3 yc=1 re5
for center (h , k) and rdius r
x^2 + 6x + y^2 - 2y = 15
x^2 + 6x + 9 + y^2 - 2y + 1 = 15 + 9 + 1 = 25
(x + 3)^2 + (y - 1)^2 = 25
comparing to the standard form:
center (h , k) is (-3 , 1)
r^2 = 25 > radius r = 5
Center (-3,1)
xc= -3 yc=1 re5