document.write( "Question 165742: cosxtanx=0 \n" ); document.write( "

Algebra.Com's Answer #122184 by Edwin McCravy(20056) $\"\"$ $\"About$

You can put this solution on YOUR website!

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document.write( "We have to be careful here!  We might be tempted\r\n" );
document.write( "to use the zero-factor principle. However that \r\n" );
document.write( "will lead us astray because  is not \r\n" );
document.write( "defined at ANY of the values of x for which\r\n" );
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document.write( "So do NOT do this:\r\n" );
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document.write( "Instead use the identity  to replace .\r\n" );
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document.write( "We can cancel 's as long as we are careful \r\n" );
document.write( "not to allow any values of x which cause the \r\n" );
document.write( "denominator  to be zero.\r\n" );
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document.write( "That leaves:\r\n" );
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document.write( "which has solution \r\n" );
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document.write( ", where n is any integer.\r\n" );
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document.write( "And this is a valid solution since \r\n" );
document.write( "is always either  or , and never .\r\n" );
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document.write( "Edwin

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