In the xy-plane, an equation of circle A is . Circle B has the same center as circle A but has a radius that is twice the radius of circle A. Which equation represents circle B?
Explanation
Answer: B.
Explanation:1. Recall the standard equation of a circle: The equation of a circle with center and radius is .
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Determine the center and radius of Circle A: The equation of Circle A is . From this equation: The center of Circle A is . The radius squared of Circle A is . So, the radius of Circle A is .
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Determine the center and radius of Circle B: Circle B has the same center as Circle A. So, the center of Circle B is also . The radius of Circle B () is twice the radius of Circle A. .
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Calculate the radius squared for Circle B: .
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Write the equation for Circle B: Using the standard form , with center and : The equation of Circle B is .
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Check the solution with the options: The equation for Circle B is . This matches option [B].
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Conclusion: The equation that represents circle B is .