document.write( "Question 103632: x^2+y^2=6y sketch the graph of the equation. This is one of the questions that are difficult for me \n" ); document.write( "
Algebra.Com's Answer #75353 by Fombitz(32388)\"\" \"About 
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x^2+y^2=6y
\n" ); document.write( "Best bet is to complete the square for y and see where we are then.
\n" ); document.write( "\"x%5E2%2By%5E2-6y=6y-6y\"
\n" ); document.write( "\"x%5E2%2By%5E2-6y=0\"
\n" ); document.write( "Completing the square for y:
\n" ); document.write( "(y+A)^2=y^2+2A+A^2
\n" ); document.write( "If I compare terms in your equation and this equation, I see that:
\n" ); document.write( "2Ay=-6y
\n" ); document.write( "2A=-6
\n" ); document.write( "A=-3
\n" ); document.write( "Once I know A, then
\n" ); document.write( "A^2 = 9
\n" ); document.write( "If I add 9 to both sides of the equation, I get:0
\n" ); document.write( "\"x%5E2%2By%5E2-6y%2B9=9\"
\n" ); document.write( "\"x%5E2%2B%28y-3%29%5E2=9\"
\n" ); document.write( "OK. If you compare this equation with the equation of a circle of radius, R, centered at (h,k):
\n" ); document.write( "\"%28x-h%29%5E2%2B%28y-k%29%5E2=R%5E2\"
\n" ); document.write( "You get
\n" ); document.write( "\"x-h=x\"
\n" ); document.write( "\"h=0\"
\n" ); document.write( "\"y-k=y-3\"
\n" ); document.write( "\"k=3\"
\n" ); document.write( "\"R%5E2=9\"
\n" ); document.write( "\"R=3\"
\n" ); document.write( "Your equation is a circle centered at (0,3) with a radius of 3.
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