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Which equation represents a circle that contains the point -5,-3 and has a center at -2,1

2 Answers

3 votes

Answer:

C

Explanation:

User Tnkh
by
5.4k points
4 votes

Answer:

(x + 2)² + (y - 1)² = 25

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.

The radius is the distance from the centre to a point on the circle.

Calculate r using the distance formula

r = √ (x₂ - x₁ )² + (y₂ - y₁ )²

with (x₁, y₁ ) = ((- 2, 1) and (x₂, y₂ ) = (- 5, - 3)

r =
√((-5+2)^2+(-3-1)^2)

=
√((-3)^2+(-4)^2)

=
√(9+16)

=
√(25) = 5

Thus

(x -(- 2))² + (y - 1)² = 5², that is

(x + 2)² + (y - 1)² = 25 ← equation of circle

User Sethen
by
5.3k points