document.write( "Question 54567This question is from textbook elementary and intermediate algebra
\n" ); document.write( ": Im not understanding this function stuff. Can someone please explain it to me. Here is an example problem. y^2=x+1 I know that you enter a number into one of the variables and solve for the other variable, but Im not sure what makes a problem like this functional or non functional. \n" ); document.write( "

Algebra.Com's Answer #36842 by Edwin McCravy(20054) $\"\"$ $\"About$

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Im not understanding this function stuff. \r\n" );
document.write( "Can someone please explain it to me. Here \r\n" );
document.write( "is an example problem. y^2=x+1 I know that \r\n" );
document.write( "you enter a number into one of the variables \r\n" );
document.write( "and solve for the other variable, but Im not \r\n" );
document.write( "sure what makes a problem like this functional \r\n" );
document.write( "or non functional.\r\n" );
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document.write( "   Just solve \r\n" );
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document.write( "       y² = x+1\r\n" );
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document.write( "   for y.  \r\n" );
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document.write( "When you take square roots of both \r\n" );
document.write( "sides, you must include\r\n" );
document.write( "   + and -.  So\r\n" );
document.write( "             ___\r\n" );
document.write( "       y = ±Öx+1\r\n" );
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document.write( "So for every value of x, (other than x = -1 \r\n" );
document.write( "which gives only y = 0), there are two y-values.  \r\n" );
document.write( "For example when x = 0, then y = ±1.  That is, \r\n" );
document.write( "we get two y-values, both 1 and -1, for only one \r\n" );
document.write( "x-value, 0.  This is what must never be\r\n" );
document.write( "true of a function.  So therefore y² = x+1 \r\n" );
document.write( "DOES NOT represent a function.  The\r\n" );
document.write( "graph of y² = x+1 looks like this:\r\n" );
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document.write( "But the graph of a function must never pass over \r\n" );
document.write( "or under any part of itself. \r\n" );
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document.write( "

Edwin McCravy \n" ); document.write( "

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