document.write( "Question 166504: These will be the last questions. Please help
\n" ); document.write( "1. List all of the possible rational zeros of f(x)=3x^5-7x^3+2x-15.
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\n" ); document.write( "I must show my work. No textbook. Have been absent from school and have a big test on Monday. Need to know how to do these for the test.
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Algebra.Com's Answer #122706 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
# 1\r
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\n" ); document.write( "\n" ); document.write( "Any rational zero can be found through this equation\r
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\n" ); document.write( "\n" ); document.write( " where p and q are the factors of the last and first coefficients\r
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\n" ); document.write( "\n" ); document.write( "So let's list the factors of -15 (the last coefficient):\r
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\n" ); document.write( "\n" ); document.write( "Now let's list the factors of 3 (the first coefficient):\r
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\n" ); document.write( "\n" ); document.write( "Now let's divide each factor of the last coefficient by each factor of the first coefficient\r
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\n" ); document.write( "\n" ); document.write( "Now simplify\r
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\n" ); document.write( "\n" ); document.write( "These are all the distinct rational zeros of the function that could occur\r
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\n" ); document.write( "\n" ); document.write( "# 2\r
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\n" ); document.write( "\n" ); document.write( "Now let's use Descartes Rule of Signs to find the number of positive, negative,and imaginary zeros.\r
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\n" ); document.write( "\n" ); document.write( "First count the sign changes of \"f%28x%29=9x%5E3-7x%5E2%2B10x-4\"\r
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\n" ); document.write( "\n" ); document.write( "From \"9x%5E3\" to \"-7x%5E2\", there is a sign change from positive to negative \r
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\n" ); document.write( "\n" ); document.write( "From \"-7x%5E2\" to \"10x\", there is a sign change from negative to positive \r
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\n" ); document.write( "\n" ); document.write( "From \"10x\" to \"-4\", there is a sign change from positive to negative \r
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\n" ); document.write( "\n" ); document.write( "So there are 3 sign changes for the expression \"f%28x%29=9x%5E3-7x%5E2%2B10x-4\". \r
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\n" ); document.write( "\n" ); document.write( "So there are 3 or 1 positive zeros\r
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\n" ); document.write( "\n" ); document.write( "So if there are 3 positive zeros, then there will be NO imaginary zeros (since there a total of 3 zeros)\r
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\n" ); document.write( "\n" ); document.write( "Or...\r
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\n" ); document.write( "\n" ); document.write( "If there is only 1 positive zero, then there will be 2 imaginary zeros.\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-x%29=9%28-x%29%5E3-7%28-x%29%5E2%2B10%28-x%29-4\" Now let's replace each \"x\" with \"-x\"\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-x%29=-9x%5E3-7x%5E2-10x-4\" Simplify\r
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\n" ); document.write( "\n" ); document.write( "Now let's count the sign changes of \"f%28-x%29=-9x%5E3-7x%5E2-10x-4\"\r
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\n" ); document.write( "\n" ); document.write( "From \"-9x%5E3\" to \"-7x%5E2\", there is no change in sign\r
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\n" ); document.write( "\n" ); document.write( "From \"-7x%5E2\" to \"-10x\", there is no change in sign\r
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\n" ); document.write( "\n" ); document.write( "From \"-10x\" to \"-4\", there is no change in sign\r
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\n" ); document.write( "\n" ); document.write( "So there are no sign changes for the expression \"f%28-x%29=-9x%5E3-7x%5E2-10x-4\"\r
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\n" ); document.write( "\n" ); document.write( "So there are 0 negative zeros\r
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\n" ); document.write( "\n" ); document.write( "Answer:\r
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\n" ); document.write( "\n" ); document.write( "So here are the possibilities:\r
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\n" ); document.write( "\n" ); document.write( "3 positive zeros, 0 negative zeros, and 0 imaginary zeros\r
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\n" ); document.write( "\n" ); document.write( "Or...\r
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\n" ); document.write( "\n" ); document.write( "1 positive zero, 0 negative zeros, and 2 imaginary zeros
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