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Find an equation of the circle that has center (1,-4) and passes through (-3,0).

User Jasonz
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1 Answer

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Explanation:

the standard form of a circle equation is

(x - h)² + (y - k)² = r²

where (h, k) is the center of the circle, and r is the radius.

so, we have

(x - 1)² + (y - -4)² = r²

(x - 1)² + (y + 4)² = r²

how do we get r or r² ?

by using the coordinates of the point the circle passes through :

(-3 - 1)² + (0 + 4)² = r²

(-4)² + 4² = r²

16 + 16 = r²

32 = r²

so, our equation is

(x - 1)² + (y + 4)² = 32

User Robin Davies
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