document.write( "Question 606116: Write an equation for the parabola with focus (-1,1) and directrix y= -7. \n" ); document.write( "

Algebra.Com's Answer #382124 by lwsshak3(11628) $\"\"$ $\"About$

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Write an equation for the parabola with focus (-1,1) and directrix y= -7.
\n" ); document.write( "This is an equation of a parabola that opens upwards.
\n" ); document.write( "Its standard form: (x-h)^2=4p(y-k)
\n" ); document.write( "for given parabola:
\n" ); document.write( "x-coordinate of vertex=-1
\n" ); document.write( "y-coordinate of vertex=(-7+1)/2=-3 (half way between focus and directrix on axis of symmetry)
\n" ); document.write( "vertex: (-1,-3)
\n" ); document.write( "axis of symmetry: x=-1
\n" ); document.write( "p=4 (distance from vertex to focus or directrix on the axis of symmetry)
\n" ); document.write( "4p=16
\n" ); document.write( "Equation:
\n" ); document.write( "(x+1)^2=16(y+3)
\n" ); document.write( " \n" ); document.write( "

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