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A circle is centered at the point (5, -4) and passes through the point (-3, 2).

he equation of this circle is (x +__ )∧2 + (y +___ )∧2 = ____.

User Gaylord
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1 Answer

3 votes

Answer:

The equation of the circle is (x + -5)² + (y + 4)² = 100

Explanation:

* Lets revise the standard form of the equation of the circle

- If the center of the circle is point (h , k) and the length of its radius is r,

then the equation of the circle is (x - h)² + (y - k)² = r² in standard form

* Now lets solve the problem

- The center of the circle is point (5 , -4)

∴ h = 5 and k = -4

∴ The equation of the circle is (x - 5)² + (y - -4)² = r²

∴ The equation of the circle is (x - 5)² + (y + 4)² = r²

- The circle passes through the point (-3 , 2)

- To find r substitute the x-coordinate and the y-coordinate of the

point in the equation of the circle

∵ Point (-3 , 2) is on the circle

∴ x = -3 and y = 2

∴ (-3 - 5)² + (2 + 4)² = r² ⇒ simplify it

∴ (-8)² + (6)² = r² ⇒ solve power 2

∴ 64 + 36 = r² ⇒ add the like terms

∴ 100 = r²

∵ The equation of the circle is (x - 5)² + (y + 4)² = r²

∴ The equation of the circle is (x - 5)² + (y + 4)² = 100

- To complete the form

∴ The equation of the circle is (x + -5)² + (y + 4)² = 100

User Timrael
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