document.write( "Question 545587: put in standard form and graph x^2-2x+y+7
\n" ); document.write( "find the focus and directrix
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Algebra.Com's Answer #357025 by lwsshak3(11628)\"\" \"About 
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put in standard form and graph x^2-2x+y+7
\n" ); document.write( "find the focus and directrix
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\n" ); document.write( "x^2-2x+y+7=0
\n" ); document.write( "y=-x^2+2x-7
\n" ); document.write( "complete the square
\n" ); document.write( "y=-(x^2-2x+1)-7+1
\n" ); document.write( "y=-(x-1)^2-6
\n" ); document.write( "(x-1)^2=-(y+6)
\n" ); document.write( "This equation is in standard form for a parabola: (x-h)^2=4p(y-k), with (h,k) being the (x,y) coordinates of the vertex. Parabola opens downwards.
\n" ); document.write( "For given equation:(x-1)^2=-(y+6)
\n" ); document.write( "vertex: (1,-6)
\n" ); document.write( "axis of symmetry: x=1
\n" ); document.write( "4p=1
\n" ); document.write( "p=1/4
\n" ); document.write( "Focus and directrix are p units from the vertex on the axis of symmetry
\n" ); document.write( "Focus: (1, -6+p)=(1,-6-1/4)=1,-25/4)
\n" ); document.write( "Directrix: y=-6+1/4=-23/4
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