What is the equation of a circle that has a center at (4,-1) and a radius of 8

x

2

+

y

2

−

8

x

+

2

y

−

47

=

0

Explanation:

the eqn of a circle centre  

(

a

,

b

)

and radius  

r

(

x

−

a

)

2

+

(

y

−

b

)

2

=

r

2

#we ahve

(

x

−

4

)

2

+

(

y

−

−

1

)

2

=

8

2

(

x

−

4

)

2

+

(

y

+

1

)

2

=

64

x

2

−

8

x

+

16

+

y

2

+

2

y

+

1

=

64

x

2

+

y

2

−

8

x

+

2

y

−

47

=

0

Answer link

Jim G.

Jun 25, 2018

(

x

−

4

)

2

+

(

y

+

1

)

2

=

64

Explanation:

the equation of a circle in standard form is

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

∣

∣

∣

2

2

(

x

−

a

)

2

+

(

y

−

b

)

2

=

r

2

2

2

∣

∣

∣

−−−−−−−−−−−−−−−−−−−−−−−−−−  

where  

(

a

,

b

)

are the coordinates of the centre and r

is the radius

here  

(

a

,

b

)

=

(

4

,

−

1

)

and  

r

=

8

(

x

−

4

)

2

+

(

y

−

(

−

1

)

)

2

=

8

2

(

x

−

4

)

2

+

(

y

+

1

)

2

=

64

Step-by-step explanation:

answer is 12345678900987654321234567890987654321

step-by-step explanation: