document.write( "Question 957784: Find the equation of the ellipse with the center at the origin.
\n" ); document.write( "Latus rectum 4, distance between foci 4sqrt(2).
\n" ); document.write( "I dont know of im doing it right. Here's my progress.\r
\n" ); document.write( "\n" ); document.write( "p = 4/2 = 2
\n" ); document.write( "c = 4sqrt(2)/2 = 2sqrt(2)\r
\n" ); document.write( "\n" ); document.write( "p = b^2/a
\n" ); document.write( "2 = b^2/a
\n" ); document.write( "b^2 = 2a\r
\n" ); document.write( "\n" ); document.write( "c^2 = a^2 - b^2
\n" ); document.write( "b^2 = a^2 - c^2
\n" ); document.write( "b^2 = a^2 - 8\r
\n" ); document.write( "\n" ); document.write( "p a = a^2 - c^2\r
\n" ); document.write( "\n" ); document.write( "Am I doing it the right way to solve for a? \n" ); document.write( "

Algebra.Com's Answer #585446 by Edwin McCravy(20060) $\"\"$ $\"About$

You can put this solution on YOUR website!

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document.write( "In the graph above, the green line is the latus rectum, the two red\r\n" );
document.write( "points are the foci.\r\n" );
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document.write( "The distance between the foci is given as \r\n" );
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document.write( "Since c is half the distance between foci, .\r\n" );
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document.write( "Since the latus rectum is given as 4, the y-coordinate of the\r\n" );
document.write( "point at the top of the latus rectum is 2. So the coordinates\r\n" );
document.write( "of the point at the top of the latus rectum are .\r\n" );
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document.write( "The equation of the ellipse is\r\n" );
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document.write( "(1)   \r\n" );
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document.write( "Substituting that point:\r\n" );
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document.write( "(2)  \r\n" );
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document.write( "Since  and \r\n" );
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document.write( "Substituting in (2)\r\n" );
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document.write( "That has solutions a=4, a=-4, a=2, a=-2\r\n" );
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document.write( "The only one it can be is a=4\r\n" );
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document.write( "Substituting in \r\n" );
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document.write( "So the equation of the ellipse, substituting in (1),\r\n" );
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document.write( "Edwin

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