document.write( "Question 991825: Please help me with this! Find the centre, vertices, lenght of latus rectum, foci , eccentricities of the ellipse x^2 + 9y^2 + 4x -18y - 23 = 0 \n" ); document.write( "
Algebra.Com's Answer #611573 by ikleyn(52788)\"\" \"About 
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\n" ); document.write( "x^2 + 9y^2 + 4x -18y - 23 = 0
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\n" ); document.write( "\n" ); document.write( "Complete the squares:\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2+%2B+9y%5E2+%2B+4x+-18y+-+23\" = \"%28x%2B2%29%5E2+-+4+%2B+%283y-3%29%5E2+-+9+-+23\" = \"%28x%2B2%29%5E2+%2B+3%5E2%2A%28y-1%29%5E2+-+36\". \r
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\n" ); document.write( "\n" ); document.write( "So,  you have the equation\r
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\n" ); document.write( "\n" ); document.write( "\"%28x%2B2%29%5E2\" + \"9%2A%28y-1%29%5E2%29\" = \"36\",\r
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\n" ); document.write( "\n" ); document.write( "or,  in the canonical form,\r
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\n" ); document.write( "\n" ); document.write( "\"%28x%2B2%29%5E2%2F6%5E2\" + \"%28%28y-1%29%5E2%29%2F%282%5E2%29\" = \"1\".\r
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\n" ); document.write( "\n" ); document.write( "It is a canonical equation of an ellipse. \r
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\n" ); document.write( "\n" ); document.write( "Its center is at the point  (x,y) = (-2,1).  Semi-major and semi-minor axes are  6  and  2,  respectively:  a=6  and  b=2. \r
\n" ); document.write( "\n" ); document.write( "Semi-major axis is the distance from the ellipse' center to its vertices. \r
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\n" ); document.write( "\n" ); document.write( "Linear eccentricity is  \"sqrt%286%5E2+-+2%5E2%29\" = \"sqrt%2832%29\" = \"4%2Asqrt%282%29\".  It is the distance from the ellipse's center to its foci. \r
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\n" ); document.write( "\n" ); document.write( "Next,  take the textbook and determine the rest ellipse's characteristics you need.\r
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