document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=700101>Question 700101</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Write the equation of a circle that passes through the points A(4;0) , B(0;2) and whose center belongs to the line of equation y+2x=0 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #431631 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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/cgi-bin/show-face.mpl?user=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=431631\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Write the equation of a circle that passes through the points A(4;0) , B(0;2) and whose center belongs to the line of equation y+2x=0<BR>\n" );
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document.write( "Find the center.  The center is equidistant from the 2 points and on the line.<BR>\n" );
document.write( "--> The center will be on the line that's the perpendicular bisector of the line joining the 2 points.<BR>\n" );
document.write( "The slope of lines thru the 2 points = -1/2 --> perpendicular lines have a slope of +2.<BR>\n" );
document.write( "The midpoint of A & B is (2,1)<BR>\n" );
document.write( "Using y = mx+b and (2,1) --> y = 2x - 3 is the perp. bisecting line.<BR>\n" );
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document.write( "The center is the intersection of y = 2x-3 and y+2x = 0<BR>\n" );
document.write( "--> (3/4,-3/2)<BR>\n" );
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document.write( "The radius is the distance from the center to either A or B<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%5E2+=+3.25%5E2+%2B+1.5%5E2+=+12.8125 ALIGN=MIDDLE  ALT=\"r%5E2+=+3.25%5E2+%2B+1.5%5E2+=+12.8125\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "the circle is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x+-+3%2F4%29%5E2+%2B+%28y+%2B+3%2F2%29%5E2+=+12.8125 ALIGN=MIDDLE  ALT=\"%28x+-+3%2F4%29%5E2+%2B+%28y+%2B+3%2F2%29%5E2+=+12.8125\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "PS  Use commas for points, eg, (4,0) and (0,2)<BR>\n" );
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