document.write( "Question 530608: find the vertex,focus,axis and directrix of the equation
\n" ); document.write( "y^2-4y-4x-8=0
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Algebra.Com's Answer #350610 by lwsshak3(11628)\"\" \"About 
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find the vertex,focus,axis and directrix of the equation
\n" ); document.write( "y^2-4y-4x-8=0
\n" ); document.write( "complete the square
\n" ); document.write( "(y^2-4y+4)=4x+8+4
\n" ); document.write( "(y-2)^2=4x+12
\n" ); document.write( "(y-2)^2=4(x+3)
\n" ); document.write( "This is an equation of a parabola of the standard form: (y-k)^2=4p(x-h), (h,k) being the (x,y) coordinates of the vertex. Parabola opens rightwards.
\n" ); document.write( "For given equation:
\n" ); document.write( "vertex: (-3,2)
\n" ); document.write( "4p=4
\n" ); document.write( "p=1
\n" ); document.write( "Focus=(-3+p,2)=(-3+1,2)=(-2,2) (p units from vertex on axis of symmetry)
\n" ); document.write( "Axis of symmetry: y=2 (a horizontal line thru the vertex)
\n" ); document.write( "Directrix: x=-4 (a vertical line p units from vertex on axis of symmetry)
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