document.write( "Question 113794: Graph f(x)=x^4-4x^2\r
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\n" ); document.write( "\n" ); document.write( "First find the x-intercepts then evaluate f(-3),f(-1),f(1),f(3)
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Algebra.Com's Answer #82810 by jim_thompson5910(35256)\"\" \"About 
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\n" ); document.write( "\"f%28x%29=x%5E4-4x%5E2\" Start with the given function\r
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\n" ); document.write( "\n" ); document.write( "\"f%28x%29=x%5E2%28x%5E2-4%29\" Factor out the GCF \"x%5E2\"\r
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\n" ); document.write( "\n" ); document.write( "\"f%28x%29=x%5E2%28x-2%29%28x%2B2%29\" Factor \"x%5E2-4\" using the difference of squares to get \"%28x-2%29%28x%2B2%29\"\r
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\n" ); document.write( "\n" ); document.write( "Now to find the x-intercepts, set \"f%28x%29\" equal to zero and solve for x\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2%28x-2%29%28x%2B2%29=0\" \r
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\n" ); document.write( "\n" ); document.write( "Break up the equation using the zero product property\r
\n" ); document.write( "\n" ); document.write( "\"x%5E2=0\" , \"x-2=0\" or \"x%2B2=0\"\r
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\n" ); document.write( "\n" ); document.write( "\"x=0\" , \"x=2\" or \"x=-2\" Solve for x in each case\r
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\n" ); document.write( "\n" ); document.write( "So our solutions are \"x=0\" , \"x=2\" or \"x=-2\" which means the x-intercepts are (0,0), (2,0), and (-2,0)\r
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\n" ); document.write( "\n" ); document.write( "Notice if we graph, we get\r
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\n" ); document.write( "\n" ); document.write( "\"+graph%28+500%2C+500%2C+-10%2C+10%2C+-10%2C+10%2C+x%5E4-4x%5E2%29+\"\r
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\n" ); document.write( "\n" ); document.write( "and we can see that the x-intercepts are (0,0), (2,0), and (-2,0)\r
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\n" ); document.write( "\n" ); document.write( "Let's evaluate \"f%28-3%29\"\r
\n" ); document.write( "\n" ); document.write( "\"f%28x%29=x%5E4-4x%5E2\" Start with the given function.\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-3%29=%28-3%29%5E4-4%28-3%29%5E2\" Plug in \"x=-3\". In other words, replace each x with -3.\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-3%29=%2881%29-4%28-3%29%5E2\" Evaluate \"%28-3%29%5E4\" to get 81.\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-3%29=%2881%29-4%289%29\" Evaluate \"%28-3%29%5E2\" to get 9.\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-3%29=%2881%29-36\" Multiply -4 and 9 to get -36\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-3%29=45\" Now combine like terms\r
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\n" ); document.write( "\n" ); document.write( "-----------Now let's evaluate another value---------\r
\n" ); document.write( "\n" ); document.write( "Let's evaluate \"f%28-1%29\"\r
\n" ); document.write( "\n" ); document.write( "\"f%28x%29=x%5E4-4x%5E2\" Start with the given function.\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-1%29=%28-1%29%5E4-4%28-1%29%5E2\" Plug in \"x=-1\". In other words, replace each x with -1.\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-1%29=%281%29-4%28-1%29%5E2\" Evaluate \"%28-1%29%5E4\" to get 1.\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-1%29=%281%29-4%281%29\" Evaluate \"%28-1%29%5E2\" to get 1.\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-1%29=%281%29-4\" Multiply -4 and 1 to get -4\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-1%29=-3\" Now combine like terms\r
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\n" ); document.write( "\n" ); document.write( "-----------Now let's evaluate another value---------\r
\n" ); document.write( "\n" ); document.write( "Let's evaluate \"f%281%29\"\r
\n" ); document.write( "\n" ); document.write( "\"f%28x%29=x%5E4-4x%5E2\" Start with the given function.\r
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\n" ); document.write( "\n" ); document.write( "\"f%281%29=%281%29%5E4-4%281%29%5E2\" Plug in \"x=1\". In other words, replace each x with 1.\r
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\n" ); document.write( "\n" ); document.write( "\"f%281%29=%281%29-4%281%29%5E2\" Evaluate \"%281%29%5E4\" to get 1.\r
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\n" ); document.write( "\n" ); document.write( "\"f%281%29=%281%29-4%281%29\" Evaluate \"%281%29%5E2\" to get 1.\r
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\n" ); document.write( "\n" ); document.write( "\"f%281%29=%281%29-4\" Multiply -4 and 1 to get -4\r
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\n" ); document.write( "\n" ); document.write( "\"f%281%29=-3\" Now combine like terms\r
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\n" ); document.write( "\n" ); document.write( "-----------Now let's evaluate another value---------\r
\n" ); document.write( "\n" ); document.write( "Let's evaluate \"f%283%29\"\r
\n" ); document.write( "\n" ); document.write( "\"f%28x%29=x%5E4-4x%5E2\" Start with the given function.\r
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\n" ); document.write( "\n" ); document.write( "\"f%283%29=%283%29%5E4-4%283%29%5E2\" Plug in \"x=3\". In other words, replace each x with 3.\r
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\n" ); document.write( "\n" ); document.write( "\"f%283%29=%2881%29-4%283%29%5E2\" Evaluate \"%283%29%5E4\" to get 81.\r
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\n" ); document.write( "\n" ); document.write( "\"f%283%29=%2881%29-4%289%29\" Evaluate \"%283%29%5E2\" to get 9.\r
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\n" ); document.write( "\n" ); document.write( "\"f%283%29=%2881%29-36\" Multiply -4 and 9 to get -36\r
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\n" ); document.write( "\n" ); document.write( "\"f%283%29=45\" Now combine like terms
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