document.write( "Question 148852: Use the intermediate valve theorem to determine if the polynomial f(x)=x^3-4x^+3x+2 has a zero Ci in the interval [-3,4].\r
\n" ); document.write( "\n" ); document.write( "a). No because f(-3)*f(4)<0
\n" ); document.write( "b). Yes because f(-3)*f(4)<0
\n" ); document.write( "c). Yes because f(-3)*f(4)>0
\n" ); document.write( "d). No because f(-3)*f(4)>0
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Algebra.Com's Answer #109192 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
To find if there is a zero in the the interval [-3,4], simply evaluate the endpoints. If the function values of the endpoints have opposite signs, then there is a zero in the interval.\r
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\n" ); document.write( "\n" ); document.write( "Let's evaluate the left endpoint -3\r
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\n" ); document.write( "\n" ); document.write( "\"f%28x%29=x%5E3-4x%5E2%2B3x%2B2\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-3%29=%28-3%29%5E3-4%28-3%29%5E2%2B3%28-3%29%2B2\" Plug in \"x=-3\".\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-3%29=1%28-27%29-4%28-3%29%5E2%2B3%28-3%29%2B2\" Cube \"-3\" to get \"-27\".\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-3%29=1%28-27%29-4%289%29%2B3%28-3%29%2B2\" Square \"-3\" to get \"9\".\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-3%29=-27-4%289%29%2B3%28-3%29%2B2\" Multiply \"1\" and \"-27\" to get \"-27\".\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-3%29=-27-36%2B3%28-3%29%2B2\" Multiply \"-4\" and \"9\" to get \"-36\".\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-3%29=-27-36-9%2B2\" Multiply \"3\" and \"-3\" to get \"-9\".\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-3%29=-70\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "So \"f%28-3%29=-70\" (take note that the function value is negative)\r
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\n" ); document.write( "\n" ); document.write( "Now let's evaluate the right endpoint 4\r
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\n" ); document.write( "\n" ); document.write( "\"f%28x%29=x%5E3-4x%5E2%2B3x%2B2\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "\"f%284%29=%284%29%5E3-4%284%29%5E2%2B3%284%29%2B2\" Plug in \"x=4\".\r
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\n" ); document.write( "\n" ); document.write( "\"f%284%29=1%2864%29-4%284%29%5E2%2B3%284%29%2B2\" Cube \"4\" to get \"64\".\r
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\n" ); document.write( "\n" ); document.write( "\"f%284%29=1%2864%29-4%2816%29%2B3%284%29%2B2\" Square \"4\" to get \"16\".\r
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\n" ); document.write( "\n" ); document.write( "\"f%284%29=64-4%2816%29%2B3%284%29%2B2\" Multiply \"1\" and \"64\" to get \"64\".\r
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\n" ); document.write( "\n" ); document.write( "\"f%284%29=64-64%2B3%284%29%2B2\" Multiply \"-4\" and \"16\" to get \"-64\".\r
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\n" ); document.write( "\n" ); document.write( "\"f%284%29=64-64%2B12%2B2\" Multiply \"3\" and \"4\" to get \"12\".\r
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\n" ); document.write( "\n" ); document.write( "\"f%284%29=14\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "So \"f%284%29=14\" (take note that the function value is positive)\r
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\n" ); document.write( "\n" ); document.write( "Since the y-values of the endpoints change in sign, this means that there is a zero in the interval. If you multiply f(-3) and f(4) you'll get a negative number. So this means that the answer is b). Yes because f(-3)*f(4)<0
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