document.write( "Question 148299: (22 pts) Consider the polynomial f(x) = 2x^3 – 3x^2 – 8x – 3.\r
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document.write( "(i) By using the Rational Zero Theorem, list all possible rational zeros of the given polynomial.\r
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document.write( "(ii) Find all of the zeros of the given polynomial. Be sure to show work, explaining how you have found them.\r
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Algebra.Com's Answer #108699 by jim_thompson5910(35256) ![]() You can put this solution on YOUR website! i)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Any rational zero can be found through this equation\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So let's list the factors of -3 (the last coefficient):\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now let's list the factors of 2 (the first coefficient):\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now let's divide each factor of the last coefficient by each factor of the first coefficient\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now simplify\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "These are all the distinct rational zeros of the function that could occur\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "--------------------------------------------------------\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "ii)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "With the help of a graphing calculator, we see that -1 is a zero of \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "note: let me know if you need to find the zeros a different way.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So let's set up a synthetic division table by placing the value -1 in the upper left corner and placing the coefficients of the polynomial to the right of -1.
\n" ); document.write( "\n" ); document.write( "Start by bringing down the leading coefficient (it is the coefficient with the highest exponent which is 2)\r \n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Multiply -1 by 2 and place the product (which is -2) right underneath the second coefficient (which is -3)\r \n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Add -2 and -3 to get -5. Place the sum right underneath -2.\r \n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Multiply -1 by -5 and place the product (which is 5) right underneath the third coefficient (which is -8)\r \n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Add 5 and -8 to get -3. Place the sum right underneath 5.\r \n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Multiply -1 by -3 and place the product (which is 3) right underneath the fourth coefficient (which is -3)\r \n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Add 3 and -3 to get 0. Place the sum right underneath 3.\r \n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Since the last column adds to zero, this means that -1 is a zero of \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now lets look at the bottom row of coefficients:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The first 3 coefficients (2,-5,-3) form the quotient\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Basically \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now lets find the zeros for \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Let's use the quadratic formula to solve for x\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the zeros of |