Question

In the standard (x,y) coordinate plane, a circle with its center at (8,5) and a radius of 9 coordinate units has which of the following equations?

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(x−8)2+(y−5)2=81

(x−8)2+(y−5)2=9

(x+8)2+(y+5)2=81

(x+8)2+(y+5)2=9

(x+5)2+(y+8)2=81

Answer 1

`(x-8)^2+(y-5)^2=81`

Explanation:

equation of a circle:
`(x-a)^2+(y-b)^2=r^2`

where
`(a, b)` is the center and
`r` is the radius

Given:

• center = (8, 5)
• radius = 9

`\implies (x-8)^2+(y-5)^2=9^2`

`\implies (x-8)^2+(y-5)^2=81`