Feature

The graph of a parabola opening to the right is shown on coordinate grid with vertex at left-parenthesis negative 3 comma 1 right-parenthesis and focus at left-parenthesis negative 1 comma 1 right-parenthesis.
Question
Use the image to answer the question.
Write the standard form of the equation for the parabola shown in the graph.
(1 point)
Responses

left parenthesis y minus 1 right parenthesis squared equals 8 left parenthesis x plus 3 right parenthesis
Image with alt text: left parenthesis y minus 1 right parenthesis squared equals 8 left parenthesis x plus 3 right parenthesis

left parenthesis y minus 1 right parenthesis squared equals 2 left parenthesis x plus 3 right parenthesis
Image with alt text: left parenthesis y minus 1 right parenthesis squared equals 2 left parenthesis x plus 3 right parenthesis

left parenthesis x plus 3 right parenthesis squared equals 8 left parenthesis y minus 1 right parenthesis
Image with alt text: left parenthesis x plus 3 right parenthesis squared equals 8 left parenthesis y minus 1 right parenthesis

left parenthesis x plus 3 right parenthesis squared equals 2 left parenthesis y minus 1 right parenthesis
Image with alt text: left parenthesis x plus 3 right parenthesis squared equals 2 left parenthesis y minus 1 right parenthesis
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1 answer

To write the standard form of the equation for the parabola, we can use the following information:

  1. The vertex of the parabola is at \((-3, 1)\).
  2. The focus of the parabola is at \((-1, 1)\), which means the parabola opens to the right.

The standard form for a horizontally opening parabola is given by:

\[ (y - k)^2 = 4p(x - h) \]

where \((h, k)\) is the vertex and \(p\) is the distance from the vertex to the focus.

In this case:

  • The vertex \((h, k) = (-3, 1)\)
  • The focus is \((-1, 1)\), so the distance \(p\) from the vertex to the focus is \(2\) (since \(-1 - (-3) = 2\)).

Thus, \(4p = 4 \cdot 2 = 8\).

Now we can substitute the vertex coordinates and the value of \(4p\) into the standard form:

\[ (y - 1)^2 = 8(x + 3) \]

Therefore, the correct equation of the parabola is:

\[ \boxed{(y - 1)^2 = 8(x + 3)} \]