document.write( "Question 982925: Write the equation of the parabola with given vertex at the origin and directrix: 3x=-4 \n" ); document.write( "
Algebra.Com's Answer #603720 by josgarithmetic(39618)\"\" \"About 
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The directrix given can be expressed \"x=-4%2F3\", and y is unrestricted. This parabola has axis of symmetry being the x-axis, and since this directrix is to the left of the vertex(the origin), the parabola is concave to the right.\r
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\n" ); document.write( "\n" ); document.write( "Using the equation of form which comes from deriving from the definition of a parabola, \"4py=x%5E2\", and because the distance from your directrix and the vertex is \"abs%28-4%2F3%29=4%2F3\", this determines \"highlight_green%28p=4%2F3%29\".\r
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\n" ); document.write( "\n" ); document.write( "Substitute for p into the derived equation form.
\n" ); document.write( "\"4%284%2F3%29x=y%5E2\"\r
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\n" ); document.write( "\n" ); document.write( "Simplifiable to \"highlight%28%2816%2F3%29x=y%5E2%29\"\r
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\n" ); document.write( "\n" ); document.write( "You can also derive the equation for your description using your given directrix \"x=-4%2F3\" and the focus 4/3 units to the right of the vertex ; the focus which is ( 4/3, 0), using the definition and Distance Formula.
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