document.write( "Question 973815: Hello! I really need help with this! My teacher never gave us a lesson on this, so I am struggling through! It is all pretty much how to identify a conic, but I do not really get what that means or how to do it. Here are a few of the problems, but if you want, you can only use one of them to show me how to do the rest.\r
\n" ); document.write( "\n" ); document.write( "identify the conic represented by the equation x^2-6x = y+3\r
\n" ); document.write( "\n" ); document.write( "identify the conic with the equation 3x^2 - y^2 - 7x + 2 = 0\r
\n" ); document.write( "\n" ); document.write( "identify the conic section of the equation [(x-2)^2]/9 - [(y+2)^2]/4 = 1\r
\n" ); document.write( "\n" ); document.write( "please help me!!!
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Algebra.Com's Answer #595955 by KMST(5328)\"\" \"About 
You can put this solution on YOUR website!
Conics with axes of symmetry parallel to the x-axis and/or y-axis are easy to identify and graph.
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\n" ); document.write( "PARABOLAS have only one variable squared, and you can transform them into something like \"y=a%28x-h%29%5E2%2Bk\" or \"x=a%28y-h%29%5E2%2Bk\" with some constants \"a\" , \"h\" , and \"k\" .
\n" ); document.write( "\"x%5E2-6x=y%2B3\"
\n" ); document.write( "\"x%5E2-6x%2B9=y%2B3%2B9\"
\n" ); document.write( "\"%28x-3%29%5E2=y%2B12\"
\n" ); document.write( "\"y=%28x-3%29%5E2-12\"
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\n" ); document.write( "ELLIPSES and CIRCLES have equations that can be transformed into something like
\n" ); document.write( "\"%28x-h%29%5E2%2Fa%5E2%2B%28y-k%29%5E2%2Fb%5E2=1\"
\n" ); document.write( "With \"a=b=R\" we get a circle: \"%28x-h%29%5E2%2FR%5E2%2B%28y-k%29%5E2%2FR%5E2=1\"<--->\"%28x-h%29%5E2%2B%28y-k%29%5E2=R%5E2\" .
\n" ); document.write( "If \"a%3C%3Eb\" the circle gets stretched to make it longer in the direction of the variable atop that larger of \"a%5E2\" and \"b%5E2\" .
\n" ); document.write( "If you see an \"x%5E2\" and a \"y%5E2\" that would both have a positive coefficient if they were on the same side of the equal sign, suspect an ellipse
\n" ); document.write( "(you don't have one of those in your examples).
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\n" ); document.write( "HYPERBOLAS have equations that can be transformed into something like
\n" ); document.write( "\"%28x-h%29%5E2%2Fa%5E2-%28y-k%29%5E2%2Fb%5E2=1\" or \"%28y-k%29%5E2%2Fa%5E2-%28x-h%29%5E2%2Fb%5E2=1\" .
\n" ); document.write( "\"+%28x-2%29%5E2%2F9+-+%28y%2B2%29%5E2%2F4+=+1\"<--->\"%28x-2%29%5E2%2F3%5E2-%28y-%28-2%29%29%5E2%2F2%5E2=1\" is already it that form (no need to transform it much).
\n" ); document.write( "Its axes of symmetry are the lines \"x-2=0\" and \"y%2B2=0\" .
\n" ); document.write( "It is centered at (2,-2).
\n" ); document.write( "Your other example takes a little more work to get it into that form,
\n" ); document.write( "but you may not need to do the transformation.
\n" ); document.write( "If the terms in \"x%5E2\" and \"y%5E2\" have coefficients with opposite sign when they are on the same side of the equal sign, suspect a hyperbola.
\n" ); document.write( "\"3x%5E2+-+y%5E2+-+7x+%2B+2+=+0+\"
\n" ); document.write( "\"3%28x%5E2+-+7x%2F3%29%2B7%5E2%2F6%5E2+-+y%5E2+=+-2+\"
\n" ); document.write( "\"3%28x%5E2-7x%2F3%2B%287%2F6%29%5E2-49%2F36%29+-+y%5E2+=+-2+\"
\n" ); document.write( "\"3%28x%5E2-7x%2F3%2B%287%2F6%29%5E2%29-3%2849%2F36%29+-+y%5E2+=+-2+\"
\n" ); document.write( "\"3%28x-7%2F6%29%5E2-49%2F12+-+y%5E2+=+-2+\"
\n" ); document.write( "\"3%28x-7%2F6%29%5E2+-+y%5E2+=+49%2F12-2+\"
\n" ); document.write( "\"3%28x-7%2F6%29%5E2+-+y%5E2+=+25%2F12+\"
\n" ); document.write( "Now, I divide by \"25%2F12\" (or multiply times \"12%2F25\" , same thing) to get
\n" ); document.write( "\"3%2812%2F25%29%28x-7%2F6%29%5E2+-+%2812%2F25%29y%5E2+=+%2812%2F25%29%2825%2F12%29+\"
\n" ); document.write( "\"%2836%2F25%29%28x-7%2F6%29%5E2+-+%2812%2F25%29y%5E2+=+1\"
\n" ); document.write( "\"%28x-7%2F6%29%5E2%2F%2825%2F36%29+-+y%5E2%2F%2825%2F12%29+=+1\"
\n" ); document.write( "\"%28x-7%2F6%29%5E2%2F%285%2F6%29%5E2+-+y%5E2%2F%2825%2F12%29+=+1\"
\n" ); document.write( "That is really a hyperbola, because teachers usually do not try to trick you.
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\n" ); document.write( "NOTE:
\n" ); document.write( "If the teacher wanted to trick you, he/she could give you something that had an \"x%5E2\" and a \"-y%5E2\" , but transformed into something like
\n" ); document.write( "\"%28x-2%29%5E2-%28y%2B2%29%5E2=0\"<-->\"%28y%2B2%29%5E2=%28x-2%29%5E2\"<--->\"system%28y%2B2=x-2%2C%22or%22%2Cy%2B2=-%28x-2%29%29\"<--->\"system%28y=x-4%2C%22or%22%2Cy=-x%29\" ,
\n" ); document.write( "and that graphs as just two lines that intersect,
\n" ); document.write( "but you can call that a degenerate hyperbola,
\n" ); document.write( "a hyperbola that degenerated into those two lines.
\n" ); document.write( "You could also have something that may have an \"x%5E2\" and a \"y%5E2\" with positive coefficients on the same side of the equal sign,
\n" ); document.write( "but when transformed turned out to be a \"degenerate ellipse,\"
\n" ); document.write( "that could be a single point (as for \"x-2%7D%5E2%2F4%2By%2B2%292%2F9=0\" ),
\n" ); document.write( "or no point at all (as for \"x-2%7D%5E2%2F4%2By%2B2%292%2F9=-1\" ).
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