document.write( "Question 976504: Find the equation of the parabolaparabola with a focus of (-1,-3) and directrix of y:-1. Please explain step by step. I have a test andand I don't understand. \n" ); document.write( "
Algebra.Com's Answer #598087 by stanbon(75887)\"\" \"About 
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Find the equation of the parabolaparabola with a focus of (-1,-3) and directrix of y = -1. Please explain step by step. I have a test andand I don't understand.
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\n" ); document.write( "Plot the focus (-1,-3)
\n" ); document.write( "Draw the directrix:: y = -1
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\n" ); document.write( "Note that the directrix is above the focus
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\n" ); document.write( "\n" ); document.write( "The vertex is half-way between the focus
\n" ); document.write( "and the directrix.
\n" ); document.write( "Vertex:: (-1,-2)
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\n" ); document.write( "p is the distance from vertex to the focus::
\n" ); document.write( "p = -1
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\n" ); document.write( "Form:: (x-h) = 4p(y-k)
\n" ); document.write( "(x+1)^2 = -4(y+2)
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\n" ); document.write( "y+2 = (-1/4)(x^2 + 2x + 1)
\n" ); document.write( "y = (-1/4)x^2 - (1/2)x - (9/4)
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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