document.write( "Question 1199306: Question\r
\n" ); document.write( "\n" ); document.write( "(a) Determine whether the differential equation
\n" ); document.write( "ydx - xdy =0 is exact:
\n" ); document.write( "(b) If not, convert it into an exact differential equation_ (c) Solve this differential equation.
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Algebra.Com's Answer #833236 by mccravyedwin(406)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Ikleyn claims that one must never write \"ln(x)\" but only \"ln(|x|)\".  But most any\r\n" );
document.write( "teacher would write \"ln(x)\" and \"logb(x)\".  I suppose Ikleyn would also\r\n" );
document.write( "say that in real numbers one must never write √(x) but only √(|x|).  However,\r\n" );
document.write( "domains are well-known for these functions in real numbers.  It is not necessary\r\n" );
document.write( "to complicate the notation.\r\n" );
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document.write( "To prove deMoivre's theorem students are often taught Euler's equation:\r\n" );
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document.write( "\"e%5E%28xi%29=cos%28x%29%2Bi%2Asin%28x%29\" which implies \"e%5E%28pi%2Ai%29=-1\" or \"ln%28-1%29=pi%2Ai\"\r\n" );
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document.write( "In complex analysis, an undergraduate mathematics course, logarithms of negative\r\n" );
document.write( "numbers are well defined as complex numbers.  \r\n" );
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document.write( "Edwin
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