document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=309353>Question 309353</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Which function is one to one<BR>\n" );
document.write( "1 (1,2)(2,2)(3,5)(5,0)<BR>\n" );
document.write( "2 (1,3)(2,4)(4,1)(0,2)<BR>\n" );
document.write( "3 (1,1)(2,1)(3,4)(4,5)<BR>\n" );
document.write( "4 (0,1)(1,0)(2,0)(3,2) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #221273 by </B><A HREF=/tutors/aboutme.mpl?userid=nyc_function><B>nyc_function(2741)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=nyc_function><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=nyc_function><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=221273\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A function f from A to B is called one-to-one (or 1-1) if whenever<BR>\n" );
document.write( "f (a) = f (b) then a = b.   No element of B is the image of more than one element in A.\r<BR>\n" );
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document.write( "In other words, a one-to-one function CANNOT have repeated values for y.\r<BR>\n" );
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document.write( "Looking at your choices, the only one that does not repeat values for y is choice 2 or (1,3)(2,4)(4,1)(0,2).\r<BR>\n" );
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document.write( "Do you see that the values for y are 3, 4, 1 and 2?  None of them repeat and so this is why it is one-to-one.\r<BR>\n" );
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