To derive the equation of the circle in standard form given the center \((−1,3)\) and radius \(5\), we can use the standard form of a circle's equation, which is:
\[ (x - h)^2 + (y - k)^2 = r^2 \]
where \((h, k)\) is the center of the circle and \(r\) is the radius.
In this case:
- The center \((h, k) = (−1, 3)\)
- The radius \(r = 5\)
Now substituting these values into the equation:
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Calculate \(r^2\): \[ r^2 = 5^2 = 25 \]
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Substitute \(h\), \(k\), and \(r^2\) into the standard equation: \[ (x - (−1))^2 + (y - 3)^2 = 25 \] This simplifies to: \[ (x + 1)^2 + (y - 3)^2 = 25 \]
Therefore, the correct equation of the circle in standard form is:
\[ (x + 1)^2 + (y - 3)^2 = 25 \]
So the correct response is:
(x + 1)² + (y - 3)² = 25