document.write( "Question 66491: How do I go about converting this equation to the standard form in order to graph the conic section? 4x^2-16x+9y^2+18y=0 I know I am supposed to complete the square...Thanks a bunch. \n" ); document.write( "
Algebra.Com's Answer #47400 by rapaljer(4671)\"\" \"About 
You can put this solution on YOUR website!
Conic Sections Summary -- \"ax%5E2+%2B+cy%5E2+%2Bdx+%2B+ey+%2B+f+=+0\"\r
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\n" ); document.write( "\n" ); document.write( "If the coefficients of \"x%5E2+\" and \"y%5E2\" are of the same sign, but unequal coefficients, then the graph will be an ELLIPSE.\r
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\n" ); document.write( "\n" ); document.write( "If both coefficients are the same sign with equal coefficients, it will be a CIRCLE. \r
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\n" ); document.write( "\n" ); document.write( "If coefficients are of opposite sign, then it will be a HYPERBOLA. \r
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\n" ); document.write( "\n" ); document.write( "A PARABOLA results when there is an \"x%5E2\" but no \"y%5E2\" or a \"y%5E2\" but no \"x%5E2\". \r
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\n" ); document.write( "\n" ); document.write( "The preferred method of solving such a problem is the method of completing the square:
\n" ); document.write( "\"4x%5E2-16x%2B9y%5E2%2B18y=0\"\r
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\n" ); document.write( "\n" ); document.write( "You must first factor out the coefficients of x^2 and y^2 like this:
\n" ); document.write( "\"4%28x%5E2-4x%2B____%29%2B9%28y%5E2+%2B2y+%2B+_____%29=0\"\r
\n" ); document.write( "\n" ); document.write( "\"4%28x%5E2-4x%2B4%29%2B9%28y%5E2+%2B2y+%2B+1%29=0%2B16%2B9\"
\n" ); document.write( "\"4%28x%5E2-4x%2B4%29%2B9%28y%5E2+%2B2y+%2B+1%29=25\"\r
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\n" ); document.write( "\n" ); document.write( "This is an ellipse. The standard form for an ellipse is in a form = 1, so divide both sides of the equation by 25 to set it equal to 1.\r
\n" ); document.write( "\n" ); document.write( "\"%284%28x-2%29%5E2%29%2F25+%2B%289%28y%2B+1%29%5E2%29%2F25=25%2F25\"
\n" ); document.write( "\"%284%28x-2%29%5E2%29%2F25+%2B%289%28y%2B+1%29%5E2%29%2F25=1\"\r
\n" ); document.write( "\n" ); document.write( "Finally invert the coefficients of 4 and 9 in order to write this:
\n" ); document.write( "\"%28%28x-2%29%5E2%29%2F%2825%2F4%29+%2B%28%28y%2B+1%29%5E2%29%2F%2825%2F9%29=1\"\r
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\n" ); document.write( "\n" ); document.write( "That would be standard form for an ellipse! The center is at (2,-1), with the \"radius\" extending \"5%2F2\" units in the x direction, and \"5%2F3\" units in the y direction. \r
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\n" ); document.write( "\n" ); document.write( "R^2 at SCC\r
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