Question

Identify the center and radius of the circle with the following equation: 〖(x+3)〗^2+〖(y-1)〗^2=81

Answer 1

Answer:

centre (3 ,-1) , r=9

Explanation:

The standard form of the equation of a circle is.

∣

∣

∣

∣

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

a

a

(

x

−

a

)

2

+

(

y

−

b

)

2

=

r

2

a

a

∣

∣

−−−−−−−−−−−−−−−−−−−−−−−−−

where (a,b) are the coordinates of the center and r , the radius.

For the given equation: a = 3 , b = -1 and r = 9

hence centre = (3 ,-1) and radius = 9

Step-by-step explanation: