document.write( "Question 876373: Enter the Equation of the directrix\r
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Algebra.Com's Answer #528741 by ewatrrr(24785) $\"\"$ $\"About$

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document.write( "Hi
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document.write( "x^2+16y=0
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document.write( "y = (-1/16)x^2  V(0,0), Opening downward: -1/16 < 0
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document.write( "1/(4p) = -1/16
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document.write( "  p = -4
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document.write( "directrix is y = 4\r
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document.write( "the vertex form of a Parabola opening up(a>0) or down(a<0),  
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document.write( "where(h,k) is the vertex  and  x = h  is the Line of Symmetry
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document.write( " a = 1/4p, where  the focus is (h,k + p)
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document.write( "With Directrix y = (k - p)
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