document.write( "Question 199774: Hello!\r
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document.write( "Find all real zeros of the polynomial. Use the quadratic formula if necessary\r
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document.write( "P(x) = x^4 + x^3 - 5x^2 - 4x + 4 \r
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document.write( "thanks for your help! \n" );
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Algebra.Com's Answer #150142 by jim_thompson5910(35256)![]() ![]() ![]() You can put this solution on YOUR website! First, let's find the possible rational zeros of P(x):\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 4 (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 1 (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( "----------------------------------------------------------------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now let's see which possible roots are actually roots.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Let's see if the possible zero \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So let's make the synthetic division table for the function \n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Since the remainder \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( "Let's see if the possible zero \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So let's make the synthetic division table for the function \n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Since the remainder \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So this means that \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Note: the term \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now that you have \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "It turns out that the possible roots for \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "and that -2 is a root of \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Here's the synthetic division to prove it:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Looking at the bottom row of values (everything but the remainder), we get \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Note: this consequently means that \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now we just need to solve \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( "Notice we have a quadratic in the form of \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( "So the last two roots are \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "====================================================================================\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Answer:\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the four zeros of \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Note: if you wanted to, you could compactly write the zeros as:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "just remember that there are 4 zeros.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "If you have any questions, email me at jim_thompson5910@hotmail.com. \n" ); document.write( "Check out my website if you are interested in tutoring. \n" ); document.write( " |