document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=29296>Question 29296</A>: <I><SPAN STYLE=\"word-break: break-all;\"> what is a domain ? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #16143 by </B><A HREF=/tutors/aboutme.mpl?userid=longjonsilver><B>longjonsilver(2297)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=longjonsilver><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=longjonsilver><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=16143\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the domain of the function f(x) is all the values of x that you are allowed to put into the function, beit from the questioner or from the physical nature of the function.\r<BR>\n" );
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document.write( "eg y=2x-3. Put in the values x=3 and x=14 into this. Here the domain is 3 and 14 because i have told you it.\r<BR>\n" );
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document.write( "eg What is the domain of y=3x+2? Well, this is a straight line, so any value of x that i pick will \"work\" ie give me an answer, so here, the answer is:\r<BR>\n" );
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document.write( "\"the domain is any value of x\"<BR>\n" );
document.write( "being more strict, we are interested in the \"REAL set of numbers\" ie every number you can think of (not imaginary ones), so strictly we say:<BR>\n" );
document.write( "\"the domain is any value of x where x belongs to the Real set of numbers\"<BR>\n" );
document.write( "mathematically we don't want to write all this every time so we have a short hand:\r<BR>\n" );
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document.write( "\"the domain is any value of x where x belongs to the Real set of numbers\"<BR>\n" );
document.write( "\"the domain is xeR\" where e means \"belongs to\" and R means \"the Real set of numbers\"\r<BR>\n" );
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document.write( "eg find the domain of y=1/x.<BR>\n" );
document.write( "Now, you need to know what 1/x looks like...sketch it and learn its shape. The critical point to note is that when x=0, we get 1/0 which is infinity...it is a non-defined value for this function.\r<BR>\n" );
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document.write( "So, the domain here is \"x belongs to the Real set, but not zero\". Mathematically, this is:\r<BR>\n" );
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document.write( "\"xeR, x = 0 \" --> put a line through the \"=\" sign, to donote \"not equal to\"...i cannot do it on here.\r<BR>\n" );
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document.write( "Hope this helps.\r<BR>\n" );
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document.write( "jon.<BR>\n" );
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