document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1208024>Question 1208024</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Describe each of the following graphs in the -plane. Give justification.\r<BR>\n" );
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document.write( "A. x = 0\r<BR>\n" );
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document.write( "B. y = 0\r<BR>\n" );
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document.write( "C. x + y = 0\r<BR>\n" );
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document.write( "D. xy = 0\r<BR>\n" );
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document.write( "Let me see.\r<BR>\n" );
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document.write( "For A, the line x = 0 is the y-axis.\r<BR>\n" );
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document.write( "For B, the line y = 0 is the x-axis. \r<BR>\n" );
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document.write( "For C, the line x + y = 0 tells me that both x and y have the same number. One is negative and the other positive. It also tells me that x and y can both be zero. \r<BR>\n" );
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document.write( "For D, the line xy = 0 tells me that either x is 0 or y is 0.\r<BR>\n" );
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document.write( "You say?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #846146 by </B><A HREF=/tutors/aboutme.mpl?userid=ikleyn><B>ikleyn(52781)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ikleyn><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=ikleyn><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=846146\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> .<BR>\n" );
document.write( "Describe each of the following graphs in the -plane. Give justification.<BR>\n" );
document.write( "A. x = 0<BR>\n" );
document.write( "B. y = 0<BR>\n" );
document.write( "C. x + y = 0<BR>\n" );
document.write( "D. xy = 0\r<BR>\n" );
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document.write( "Let me see.<BR>\n" );
document.write( "For A, the line x = 0 is the y-axis.<BR>\n" );
document.write( "For B, the line y = 0 is the x-axis.<BR>\n" );
document.write( "For C, the line x + y = 0 tells me that both x and y have the same number. One is negative and the other positive. It also tells me that x and y can both be zero.<BR>\n" );
document.write( "For D, the line xy = 0 tells me that either x is 0 or y is 0.<BR>\n" );
document.write( "You say?<BR>\n" );
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document.write( "(A)  is correct.\r\n" );
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document.write( "(B)  is correct.\r\n" );
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document.write( "(C)  To be more accurate, I would say that for (C), x and y have the same absolute values, but different signs.\r\n" );
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document.write( "     The line x + y = 0  is the same as the line  y = -x.\r\n" );
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document.write( "     Geometrically, it is a straight line with the slope -1 through the origin of the coordinate system\r\n" );
document.write( "     which goes from upper left to down right, making the angle of 135 = 90 + 45 degrees with\r\n" );
document.write( "     the positive direction of x-axis.\r\n" );
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document.write( "(D)  The graph of equation  xy = 0  is the union of two straight lines.\r\n" );
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document.write( "     One line is x-axis y= 0.\r\n" );
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document.write( "     Another line is y-axis  x= 0.\r\n" );
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document.write( "     The graph also includes the origin of the coordinate system (0,0), which is the intersection of the two mentioned straight lines.\r\n" );
document.write( "</PRE>\r<BR>\n" );
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document.write( "Solved.\r<BR>\n" );
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document.write( "I am glad to see your progress.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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