document.write( "Question 723666: What are the focus and directrix of the parabola with the equation y = 1/12x2? \r
\n" ); document.write( "\n" ); document.write( "focus: (3, 0) ; directrix: y = –3
\n" ); document.write( "focus: (–3, 0) ; directrix: y = 3
\n" ); document.write( "focus: (0, 3) ; directrix: y = –3
\n" ); document.write( "focus: (0, –3) ; directrix: y = 3
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Algebra.Com's Answer #443257 by MathLover1(20850)\"\" \"About 
You can put this solution on YOUR website!
The standard equation for a parabola with its axis vertical is:\r
\n" ); document.write( "\n" ); document.write( "\"%28x+-h%29%5E2+=+4a%28y-k%29\" ...(1)\r
\n" ); document.write( "\n" ); document.write( "The vertex is (\"h\",\"+k\").
\n" ); document.write( "The focus is (\"h\",\"+k+%2B+a\").
\n" ); document.write( "The directrix is \"y+=+k+-a\".\r
\n" ); document.write( "\n" ); document.write( "you have\r
\n" ); document.write( "\n" ); document.write( "\"y+=+%281%2F12%29x%5E2+\"...solve for \"x%5E2\"\r
\n" ); document.write( "\n" ); document.write( "\"y+%2F%281%2F12%29=+x%5E2+\"\r
\n" ); document.write( "\n" ); document.write( "\"12y+=+x%5E2\" ....write it in form given above\r
\n" ); document.write( "\n" ); document.write( "\"12%28y-0%29+=+%28x-0%29%5E2+\"\r
\n" ); document.write( "\n" ); document.write( "as you can see\r
\n" ); document.write( "\n" ); document.write( "\"h=0\"
\n" ); document.write( "\"k=0\"
\n" ); document.write( "\"4a=12\"...=>...\"a=3\"\r
\n" ); document.write( "\n" ); document.write( "than,
\n" ); document.write( "the vertex is (\"h\",\"+k\")=(\"0\",\"0\")
\n" ); document.write( "the focus is (\"h\", \"k+%2B+a\")= (\"0\", \"0+%2B+3\")=(\"0\",\"+3\")
\n" ); document.write( "the directrix is \"y+=+k+-a\"...=>..\"y+=+0-3\"...=>..\"y+=-3\"\r
\n" ); document.write( "\n" ); document.write( "so, your answer is: \r
\n" ); document.write( "\n" ); document.write( "focus: (\"0\",\"+3\") ; directrix: \"y+=-3\"\r
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