document.write( "Question 1182855: The nature of the roots of the equation 3x^4 + 4x^3 + x - 1 = 0 is _____.\r
\n" ); document.write( "\n" ); document.write( "A. Three positive real roots and one negative real root.
\n" ); document.write( "B. Three negative real roots and one positive real root.
\n" ); document.write( "C. One negative real root and three complex roots.
\n" ); document.write( "D. One positive real root, one negative real root and two complex roots.\r
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\n" ); document.write( "\n" ); document.write( "--> Please help me on answering the correct nature of the roots on the equation and correct steps of doing it. Thank you so much!
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Algebra.Com's Answer #812948 by MathLover1(20849)\"\" \"About 
You can put this solution on YOUR website!
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\n" ); document.write( "\n" ); document.write( "The nature of the roots of the equation\r
\n" ); document.write( "\n" ); document.write( "\"3x%5E4+%2B+4x%5E3+%2B+x+-+1+=+0+\"\r
\n" ); document.write( "\n" ); document.write( "observe sign changes\r
\n" ); document.write( "\n" ); document.write( "signs are:
\n" ); document.write( "\"3x%5E4+%2B+4x%5E3+%2B+x+-+1+\"
\n" ); document.write( "+ + + -\r
\n" ); document.write( "\n" ); document.write( "=> number of sign changes is \"1\"
\n" ); document.write( "it means => number of positive roots is \"1\"\r
\n" ); document.write( "\n" ); document.write( "now replace \"x\" with \"-x\" and observe sign changes\r
\n" ); document.write( "\n" ); document.write( "\"3%28-x%29%5E4+%2B+4%28-x%29%5E3+%2B+%28-x%29+-+1+\"\r
\n" ); document.write( "\n" ); document.write( "\"3x%5E4+-4x%5E3+-x+-+1\"
\n" ); document.write( "+ - - -\r
\n" ); document.write( "\n" ); document.write( "=> number of sign changes is \"1\"\r
\n" ); document.write( "\n" ); document.write( "=> number of negative roots of original polynomial is\"+1\"\r
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\n" ); document.write( "\n" ); document.write( "so,
\n" ); document.write( "=> number of positive roots is \"1\"
\n" ); document.write( "=> number of negative roots of original polynomial is \"1\" and
\n" ); document.write( "=> number of imaginary roots of original polynomial is:
\n" ); document.write( "\"n-%28p%2Bq%29\" .......where \"n\" is number of degree,\"+p\" is number of positive roots, \"q\" is number of negative roots\r
\n" ); document.write( "\n" ); document.write( "\"n=4\",\"p=1\",\"q=1\"\r
\n" ); document.write( "\n" ); document.write( "\"n-%28p%2Bq%29+=4-%281%2B1%29=2\"\r
\n" ); document.write( "\n" ); document.write( "=> number of imaginary roots is \"2\"\r
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\n" ); document.write( "\n" ); document.write( "then answer is\r
\n" ); document.write( "\n" ); document.write( "D. One positive real root, one negative real root and two complex roots\r
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