26.8k views
3 votes
What is the equation of this circle in standard form?

(x−1)2+(y−2)2=7

(x+1)2+(y+2)2=7

(x+1)2+(y+2)2=49

(x−1)2+(y−2)2=49
A circle on a coordinate plane centered at begin ordered pair negative 1 comma negative 2 end ordered pair. The horizontal x-axis ranges from negative 10 to 10 increments of 1. The vertical y-axis ranges from negative 10 to 10 in increments of 1. The circle passes through begin ordered pair negative 6 comma negative 2 end ordered pair, begin ordered pair negative 1 comma 5 end ordered pair, begin ordered pair 6 comma negative 2 end ordered pair, and begin ordered pair negative 1 comma negative 9 end ordered pair.

User TVK
by
6.1k points

1 Answer

1 vote

Answer:

Option C.

Explanation:

Note : In the given points one point is (8,-2) instead of (-6,-2).

The standard form of a circle is


(x-h)^2+(y-k)^2=r^2

where, (h,k) is center of circle and r is radius.

It is given that center of the circle is (-1,-2). So,


h=-1,k=-2


(x-(-1))^2+(y-(-2))^2=r^2


(x+1)^2+(y+2)^2=r^2 ...(1)

It is given that the circle passing through the point (8,-2),(-1,5),(6,-2),(-1,-9).

Substitute x=6 and y=-2 in equation (1).


(6+1)^2+(-2+2)^2=r^2


(7)^2+(0)^2=r^2


49=r^2

Substitute
r^2=49 in equation (1).


(x+1)^2+(y+2)^2=49

Therefore, the correct option is C.

User Vvondra
by
6.4k points