Question

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What are the coordinates of the center of the circle and radius of the circle whose equation is (x+2)^2+(y – 1)^2 = 45?
Enter your answer by filling in the boxes. Enter irrational values in simplest radical form, if necessary.
center:
radius =

Answer 1

centre = (- 2, 1 ) , r = 3
`√(5)`

Explanation:

The equation of a circle in standard form is

(x - h)² + (y - k)² = r²

where (h, k ) are the coordinates of the centre and r is the radius

(x + 2)² + (y - 1)² = 45 ← is in standard form

with centre = (- 2, 1 ) and r =
`√(45)` = 3
`√(5)`