document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=870522>Question 870522</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Is this a function? Explain why or why not<BR>\n" );
document.write( "(3,5) (-2,4) (9,1) (7,5) (1,1) (3,4) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #524905 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=524905\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Notice how we have the two points (3,5) and (3,4). This x value (x = 3) corresponds to two y values (y = 5, y = 4). So that means it's NOT a function. Each x value must correspond to EXACTLY ONE y value for it to be a function.\r<BR>\n" );
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document.write( "Visually, you can plot all of these points. Then you would see that they fail the vertical line test because a vertical line passes through more than one point when you get to (3,5) and (3,4).\r<BR>\n" );
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document.write( "Question: <font color=\"blue\">Is this a function? <BR>\n" );
document.write( "(3,5) (-2,4) (9,1) (7,5) (1,1) (3,4)</font>\r<BR>\n" );
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document.write( "Answer: <font color=\"red\">No, it's not a function</font> (reasoning explained above) </SPAN>\n" );
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