document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=90609>Question 90609</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Determine if the relation is a function.<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 #66838 by </B><A HREF=/tutors/aboutme.mpl?userid=mathispowerful><B>mathispowerful(115)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=mathispowerful><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=66838\">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=1%2By%5E2 ALIGN=MIDDLE  ALT=\"x%5E2=1%2By%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "solve for y:\r<BR>\n" );
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document.write( "y = +/-<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%28x%5E2-1%29 ALIGN=MIDDLE  ALT=\"sqrt%28x%5E2-1%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "you can see that for each x value, there will be 2 y values, that means y value<BR>\n" );
document.write( "is not unique, according to the definition of function, it is not a function. </SPAN>\n" );
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