To find the equation of a parabola given a focus and a directrix, we can follow these steps:
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Identify the Focus and Directrix:
- Focus: \( (10, -3) \)
- Directrix: \( x = 2 \)
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Determine the Orientation: Since the focus is to the right of the directrix, the parabola opens to the right.
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Find the Vertex: The vertex lies midway between the focus and the directrix. To find the x-coordinate of the vertex:
- The x-coordinates of the focus and the directrix are \(10\) and \(2\), respectively.
- The x-coordinate of the vertex is: \[ \frac{10 + 2}{2} = \frac{12}{2} = 6 \] The y-coordinate remains the same as the focus \( -3 \).
- Vertex: \( (6, -3) \)
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Find the value of \(p\): The distance \(p\) from the vertex to the focus (or vertex to directrix) is: \[ p = 10 - 6 = 4 \]
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Write the Equation: The standard form of a parabola that opens to the right, with vertex \((h, k)\) is: \[ (y - k)^2 = 4p(x - h) \] Here:
- \(h = 6\)
- \(k = -3\)
- \(p = 4\)
Substituting in these values: \[ (y + 3)^2 = 16(x - 6) \]
Thus, the equation of the parabola is: \[ (y + 3)^2 = 16(x - 6) \]
Among the options you provided, this equation corresponds to: \[ \text{(x−6)²=16(y+3)} \] This represents the correct form of the equation of the parabola.