document.write( "Question 1127820: Someone please help me with this question.\r
\n" ); document.write( "\n" ); document.write( "What are the factors of the polynomial function?\r
\n" ); document.write( "\n" ); document.write( "Use the rational root theorem to determine the factors.\r
\n" ); document.write( "\n" ); document.write( "\"+f%28x%29=+2x%5E3+%2B+x%5E2+-+8x+-+4++\"\r
\n" ); document.write( "\n" ); document.write( "Select EACH correct answer.\r
\n" ); document.write( "\n" ); document.write( "A. (2x + 1)\r
\n" ); document.write( "\n" ); document.write( "B. (2x - 1)\r
\n" ); document.write( "\n" ); document.write( "C. (x + 2)\r
\n" ); document.write( "\n" ); document.write( "D. (x - 2)\r
\n" ); document.write( "\n" ); document.write( "E. (x - 1)\r
\n" ); document.write( "\n" ); document.write( "F. (x + 1)\r
\n" ); document.write( "\n" ); document.write( "G. (x - 4)\r
\n" ); document.write( "\n" ); document.write( "H. (x + 4)
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Algebra.Com's Answer #744278 by greenestamps(13200)\"\" \"About 
You can put this solution on YOUR website!


\n" ); document.write( "The rational roots theorem says that the possible rational roots for a polynomial are +/-(p/q), where p is a factor of the constant term and q is a factor of the leading coefficient. For this polynomial then, the possible roots are

\n" ); document.write( "+/- {1, 2, 4, 1/2}

\n" ); document.write( "When you find one root, you can divide the polynomial by the corresponding linear factor to obtain a quadratic polynomial; you can then find the other two roots by factoring the quadratic or using the quadratic formula.

\n" ); document.write( "So you only need to find one root using the rational roots theorem. Which ones should you try first?

\n" ); document.write( "1 and -1 are always the easiest to test, simply by evaluating the polynomial for those values. In this example, neither 1 nor -1 is a root.

\n" ); document.write( "For the other possible rational roots, some students will prefer evaluating the polynomial; other students will find synthetic division easier. Try the smaller integers (positive and negative) first. And hope that you find a root before you need to test the fractions.

\n" ); document.write( "In this example, the polynomial evaluated at x=2 is 0, so 2 is a root. Dividing the polynomial by the linear factor (x-2) using synthetic division shows the remaining polynomial to be 2x^2+5x+2. That is easily factored to finish the factorization of the polynomial.
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