document.write( "Question 86393: Hi I need helping trying to determine if an equation is a function... I just don't understand\r
\n" ); document.write( "\n" ); document.write( "here are some examples:\r
\n" ); document.write( "\n" ); document.write( "x + 2y =4\r
\n" ); document.write( "\n" ); document.write( "x^2 + 5y^2 =1\r
\n" ); document.write( "\n" ); document.write( "x^2 + y-7 =0\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
Algebra.Com's Answer #62502 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
Solve each problem for y:\r
\n" ); document.write( "\n" ); document.write( "x + 2y =4
\n" ); document.write( "y = (-1/2)x+2
\n" ); document.write( "For each value of x there will be one value for y so it is a function.
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\n" ); document.write( "x^2 + 5y^2 =1
\n" ); document.write( "5y^2=-x^2+1
\n" ); document.write( "y^2 = (1-x^2)/5
\n" ); document.write( "y= + sqrt[(1-x^2)/5] or y=-[sqrt[(1-x^2)/5]
\n" ); document.write( "For each value of x there will be two values for y so it is NOT a function.
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\n" ); document.write( "x^2 + y-7 =0
\n" ); document.write( "y = -x^2-7
\n" ); document.write( "For each value of x there will be one value for y so it is a function.
\n" ); document.write( "===============
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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