document.write( "Question 1022162: Which is not a function?
\n" ); document.write( "(x,1)(z,w)(w,z)
\n" ); document.write( "(x,1)(y,1)(w,1)
\n" ); document.write( "(x,y)(y,y)(w,y)
\n" ); document.write( "All
\n" ); document.write( "None\r
\n" ); document.write( "\n" ); document.write( "plz explain too \n" ); document.write( "
Algebra.Com's Answer #637914 by Edwin McCravy(20054)\"\" \"About 
You can put this solution on YOUR website!
\r\n" );
document.write( "To put it is more concisely:\r\n" );
document.write( "\r\n" );
document.write( "To have a function, \r\n" );
document.write( "\r\n" );
document.write( "The FIRST coordinates must ALL be DIFFERENT!\r\n" );
document.write( "\r\n" );
document.write( "(It doesn't matter if some of the SECOND coordinates\r\n" );
document.write( "are the same, or if they are the same as some of the\r\n" );
document.write( "FIRST coordinates.  We go only by the FIRST coordinates)\r\n" );
document.write( "------------------------------------------\r\n" );
document.write( "\r\n" );
document.write( "{(x,1)(z,w)(w,z)} IS a function because the 3 FIRST coordinates\r\n" );
document.write( "x, z and w are all different.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "{(x,1)(y,1)(w,1)} IS a function because the 3 FIRST coordinates\r\n" );
document.write( "x, y and w are all different.  It doesn't matter that the SECOND\r\n" );
document.write( "coordinates are the same. \r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "{(x,y)(y,y)(w,y)} IS a function because the 3 FIRST coordinates\r\n" );
document.write( "x, y and w are all different.  Again, it doesn't matter that the \r\n" );
document.write( "SECOND coordinates are the same. \r\n" );
document.write( "\r\n" );
document.write( "Edwin
\n" ); document.write( "
\n" );