document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1039162>Question 1039162</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Which function has an inverse that is also a function?\r<BR>\n" );
document.write( "\n" );
document.write( "{(-4,3),(-2,7),(-1,0),(4,3),(11,-7)}\r<BR>\n" );
document.write( "\n" );
document.write( "{(-4,6),(-2,2),(-1,6),(4,2),(11,2)}\r<BR>\n" );
document.write( "\n" );
document.write( "{(-4,5),(-2,9),(-1,8),(4,8),(11,4)}\r<BR>\n" );
document.write( "\n" );
document.write( "{(-4,4),(-2,-1),(-1,0),(4,1),(11,1)} </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #659456 by </B><A HREF=/tutors/aboutme.mpl?userid=richard1234><B>richard1234(7193)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=richard1234><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=richard1234><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=659456\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> None of those functions have inverses that are functions -- for the inverse to be a function, the inverse relation must satisfy the property that each input maps to at most one output.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "For example, the first function's inverse is not a function since the inverse is {(3,-4), (7,-2), (0,-1), (3,4), (-7,11)}, and here we see that 3 maps to two values (-4 and 4).\r<BR>\n" );
document.write( "\n" );
document.write( "The same holds for the other functions. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );