document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=867565>Question 867565</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Convert the rectangular equation to polar form. (Use r and use theta for &#952; as necessary.)<BR>\n" );
document.write( "x2 + y2 = 18<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 #523079 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=523079\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5E2%2By%5E2=18 ALIGN=MIDDLE  ALT=\"x%5E2%2By%5E2=18\"   DISABLED_style= \"max-width:90%; height:auto;\" >, which is really <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x-0%29%5E2%2B%28y-0%29%5E2=%28sqrt%2818%29%29%5E2 ALIGN=MIDDLE  ALT=\"%28x-0%29%5E2%2B%28y-0%29%5E2=%28sqrt%2818%29%29%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > is in the form <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;\" > which is a circle with center (h,k) = (0,0) and radius <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%5E2=18 ALIGN=MIDDLE  ALT=\"r%5E2=18\"   DISABLED_style= \"max-width:90%; height:auto;\" > ---> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r+=+sqrt%2818%29 ALIGN=MIDDLE  ALT=\"r+=+sqrt%2818%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Now simplify <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r+=+sqrt%2818%29 ALIGN=MIDDLE  ALT=\"r+=+sqrt%2818%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r+=+sqrt%2818%29 ALIGN=MIDDLE  ALT=\"r+=+sqrt%2818%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r+=+sqrt%289%2A2%29 ALIGN=MIDDLE  ALT=\"r+=+sqrt%289%2A2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r+=+sqrt%289%29%2Asqrt%282%29 ALIGN=MIDDLE  ALT=\"r+=+sqrt%289%29%2Asqrt%282%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r+=+3%2Asqrt%282%29 ALIGN=MIDDLE  ALT=\"r+=+3%2Asqrt%282%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "So the answer, as simplified as possible, is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r+=+3%2Asqrt%282%29 ALIGN=MIDDLE  ALT=\"r+=+3%2Asqrt%282%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >. This is because this is simply a circle with radius <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3%2Asqrt%282%29 ALIGN=MIDDLE  ALT=\"3%2Asqrt%282%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > and when you have something like <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r+=+2 ALIGN=MIDDLE  ALT=\"r+=+2\"   DISABLED_style= \"max-width:90%; height:auto;\" >, you mean \"a circle with center (0,0) with radius 2\" </SPAN>\n" );
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