document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=98840>Question 98840</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0130800066/algebrahomeworkh></A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> one question: about finding center and radius  (circle graph) : \r<BR>\n" );
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document.write( "i did this:\r<BR>\n" );
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document.write( "(3x^2 -6x) + (3y^2 +12y)=0\r<BR>\n" );
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document.write( "then I complete the square:\r<BR>\n" );
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document.write( "-6/2 = -3^2=9    and   12/2 =6^2=36\r<BR>\n" );
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document.write( "then:\r<BR>\n" );
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document.write( "(3x^2-6x+9) + (3y^2+12y+36)= 9+36\r<BR>\n" );
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document.write( "(3x-3)^2 + (3y +6)^2 =45\r<BR>\n" );
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document.write( "factor:\r<BR>\n" );
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document.write( "3(x-1) + 3(y+2)= 45\r<BR>\n" );
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document.write( "i got the answer for center:\r<BR>\n" );
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document.write( "C(1,-2) \r<BR>\n" );
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document.write( "and the answer to the raduis is square root of 5\r<BR>\n" );
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document.write( "which i dont know how they got it.\r<BR>\n" );
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document.write( "thank you\r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #71911 by </B><A HREF=/tutors/aboutme.mpl?userid=Earlsdon><B>Earlsdon(6294)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Earlsdon><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=71911\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Well, your error is found in the step...\"completing the square\"<BR>\n" );
document.write( "Let's go over that:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3x%5E2-6x%2B3y%5E2%2B12y+=+0 ALIGN=MIDDLE  ALT=\"3x%5E2-6x%2B3y%5E2%2B12y+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > then you said ...\"complete the square\", but before you do that, you should factor out a 3 then divide through by 3 and you will get:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3%28x%5E2-2x%2By%5E2%2B4%29+=+0 ALIGN=MIDDLE  ALT=\"3%28x%5E2-2x%2By%5E2%2B4%29+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > Divide both sides by 3.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5E2-2x%2By%5E2%2B4y+=+0 ALIGN=MIDDLE  ALT=\"x%5E2-2x%2By%5E2%2B4y+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > Now you complete the square when the coefficients of the <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5E2 ALIGN=MIDDLE  ALT=\"x%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y%5E2 ALIGN=MIDDLE  ALT=\"y%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > terms are equal to 1.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x%5E2-2x%2B1%29%2B%28y%5E2%2B4y%2B4%29+=+1%2B4 ALIGN=MIDDLE  ALT=\"%28x%5E2-2x%2B1%29%2B%28y%5E2%2B4y%2B4%29+=+1%2B4\"   DISABLED_style= \"max-width:90%; height:auto;\" > Factor the trinomials.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x-1%29%5E2%2B%28y%2B2%29%5E2+=+5 ALIGN=MIDDLE  ALT=\"%28x-1%29%5E2%2B%28y%2B2%29%5E2+=+5\"   DISABLED_style= \"max-width:90%; height:auto;\" > Now compare this with the standard form for a circle of radius r and center at (h, k).<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x-h%29%5E2%2B%28y-k%29%5E2+=+r%5E2 ALIGN=MIDDLE  ALT=\"%28x-h%29%5E2%2B%28y-k%29%5E2+=+r%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" >and you can see that h = 1, k = -2, and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%5E2+=+5 ALIGN=MIDDLE  ALT=\"r%5E2+=+5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The center (h, k) is at (1, -2) and the radius is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r+=+sqrt%285%29 ALIGN=MIDDLE  ALT=\"r+=+sqrt%285%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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