\r\n" );
document.write( "Fractional exponents must be avoided in mathematics courses \r\n" );
document.write( "less advanced than complex analysis. In complex analysis \r\n" );
document.write( "there are \"multi-valued functions\".\r\n" );
document.write( "\r\n" );
document.write( "There are two square roots of, say, 4, +2 and -2.\r\n" );
document.write( "However, in math courses less advanced than complex analysis,\r\n" );
document.write( "we restrict the symbol
to mean only the positive\r\n" );
document.write( "square root of 4, not -2. If we want the other square root,\r\n" );
document.write( "-2, we must write
. That agreement was made \r\n" );
document.write( "so that the square root relation would be a function, passing \r\n" );
document.write( "the vertical line test.\r\n" );
document.write( "\r\n" );
document.write( "But imaginary (complex) numbers are neither positive nor \r\n" );
document.write( "negative, so no such agreement is possible. +i is neither a \r\n" );
document.write( "positive number nor a negative number. Likewise -i is neither\r\n" );
document.write( "a negative number nor a positive number. \r\n" );
document.write( "\r\n" );
document.write( "So
\r\n" );
document.write( "\r\n" );
document.write( "and its equivalent expression \r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "actually is double valued and means both the values,\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "but that is in the more advanced course complex analysis.\r\n" );
document.write( "\r\n" );
document.write( "Until we study the advanced mathematics course of complex\r\n" );
document.write( "analysis, we must avoid writing radicals or fraction\r\n" );
document.write( "exponents of negative or imaginary numbers.\r\n" );
document.write( "\r\n" );
document.write( "Therefore
may not be written as \r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "in lower math courses because it involves a fractional \r\n" );
document.write( "exponent of an imaginary number.\r\n" );
document.write( "\r\n" );
document.write( "Edwin
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document.write( "