document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=993704>Question 993704</A>: <I><SPAN STYLE=\"word-break: break-all;\"> How do I determine the graph on a coordinate axis to be a function?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #612920 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=612920\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Use the vertical line test.  Take a piece of paper with an edge parallel to the y-axis and move it across the graph.  The paper should touch the graph no more than once.<BR>\n" );
document.write( "y=x^2 is a function.<BR>\n" );
document.write( "x=y^2 is not a function.  <BR>\n" );
document.write( "Circles are not functions. </SPAN>\n" );
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