document.write( "Question 142440:
\n" ); document.write( " For f(x)=-2x^5+3x^4-6x^2+1 what does Descartes rule of signs tell you about
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Algebra.Com's Answer #103747 by Edwin McCravy(20056)\"\" \"About 
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For f(x)=-2x^5+3x^4-6x^2+1 what does Descartes rule of signs tell you about
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document.write( "f(x) = -2x5 + 3x4 - 6x2 + 1\r\n" );
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document.write( "The signs go:\r\n" );
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document.write( "       -    +     -     +         \r\n" );
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document.write( "That makes 3 sign changes.  So there are either\r\n" );
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document.write( "3 positive real zeros or\r\n" );
document.write( "2 less than 3 positive real zeros\r\n" );
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document.write( "Answer: There are either 3 or 1 positive real zeros.\r\n" );
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document.write( "The number of negative real zeros?\r\n" );
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document.write( "Now find f(-x)\r\n" );
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document.write( "f(x) = -2x5 + 3x4 - 6x2 + 1\r\n" );
document.write( "f(-x) = -2(-x)5 + 3(-x)4 - 6(-x)2 + 1\r\n" );
document.write( "f(-x) = -2(-x5) + 3x4 - 6x2 + 1\r\n" );
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document.write( "f(-x) = +2x5 + 3x4 -6x2 + 1\r\n" );
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document.write( "Erasing all but the signs:\r\n" );
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document.write( "        +    +     -    +\r\n" );
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document.write( "There are two sign changes, so \r\n" );
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document.write( "2 negative real zeros or\r\n" );
document.write( "2 less than 2 negative real zeros\r\n" );
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document.write( "Answer: There are either 2 or 0 negative real zeros.\r\n" );
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document.write( "Edwin
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