Q. x2+y2−6x+14y=6What is the length of the diameter of the circle whose equation is shown?
Equation in Standard Form: The given equation is x2+y2−6x+14y=6. To find the length of the diameter, we first need to write the equation in the standard form of a circle, which is (x−h)2+(y−k)2=r2, where (h,k) is the center of the circle and r is the radius.
Completing the Square: We complete the square for the x-terms and the y-terms in the equation. For the x-terms, we take the coefficient of x, which is −6, divide it by 2 to get −3, and then square it to get 9. We add and subtract this value inside the equation. For the y-terms, we take the coefficient of y, which is 14, divide it by 2 to get 7, and then square it to get 49. We add and subtract this value inside the equation as well.
Rewriting the Equation: The equation becomes x2−6x+9+y2+14y+49=6+9+49. We added 9 and 49 to both sides of the equation to keep the equation balanced.
Identifying the Center and the Radius Squared: Now, we can rewrite the equation as (x−3)2+(y+7)2=64. This is the standard form of the equation of a circle, where the center is at (h,k)=(3,−7) and the radius squared, r2, is 64.
Calculating the Radius: To find the radius r, we take the square root of 64, which gives us r=8.
Calculating the Diameter: The diameter d of a circle is twice the radius. Therefore, the diameter is d=2×r. Substituting the value of the radius we found, we get d=2×8=16.
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