document.write( "Question 870622: Find the equation of the parabola with focus F(4,0) and directrix x=3 by using the Distance formula \n" ); document.write( "

Algebra.Com's Answer #524997 by josgarithmetic(39620) $\"\"$ $\"About$

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The distance between F and any (x,y) is equal to the distance between the directrix (3,y) and (x,y).\r
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\n" ); document.write( "\n" ); document.write( " $\"sqrt%28%28x-4%29%5E2%2B%28y-0%29%5E2%29=sqrt%28%28x-3%29%5E2%2B%28y-y%29%5E2%29\"$ \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " $\"sqrt%28%28x-4%29%5E2%2By%5E2%29=sqrt%28%28x-3%29%5E2%29\"$
\n" ); document.write( " $\"%28x-4%29%5E2%2By%5E2=%28x-3%29%5E2\"$
\n" ); document.write( " $\"x%5E2-8x%2B16%2By%5E2=x%5E2-6x%2B9\"$
\n" ); document.write( " $\"-8x%2B16%2By%5E2=-6x%2B9\"$
\n" ); document.write( " $\"-2x%2B16%2By%5E2=9\"$
\n" ); document.write( " $\"-2x=-y%5E2%2B9-16\"$
\n" ); document.write( " $\"2x=y%5E2%2B16-9\"$
\n" ); document.write( " $\"2x=y%5E2%2B7\"$
\n" ); document.write( " $\"highlight%28x=%281%2F2%29y%5E2%2B7%2F2%29\"$ \n" ); document.write( "

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