document.write( "Question 189673: I am having problems finding the x-intercepts of the following problem.\r
\n" ); document.write( "\n" ); document.write( " Problem : Consider the Quadratic Function of f(x)= x^2-4x-32. Its vertex is ( ?, ?) its x-intercepts are (?,?) , its y-intercept is (?)\r
\n" ); document.write( "\n" ); document.write( "Ok, I figured out the vertex of the problem which are ( 2,-36) and the y-intercept which is (-32) but I am not sure how to get the x-intercepts. Could someone please help me?
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Algebra.Com's Answer #142312 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
X-Intercept(s):\r
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\n" ); document.write( "\n" ); document.write( "Remember, the x-intercept(s) occur when f(x) (or y) is equal to zero.\r
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\n" ); document.write( "\n" ); document.write( "\"f%28x%29=+x%5E2-4x-32\" Start with the given function.\r
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\n" ); document.write( "\n" ); document.write( "\"0=+x%5E2-4x-32\" Plug in \"f%28x%29=0\"\r
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\n" ); document.write( "\n" ); document.write( "Notice we have a quadratic equation in the form of \"ax%5E2%2Bbx%2Bc\" where \"a=1\", \"b=-4\", and \"c=-32\"\r
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\n" ); document.write( "\n" ); document.write( "Let's use the quadratic formula to solve for x\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29\" Start with the quadratic formula\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-%28-4%29+%2B-+sqrt%28+%28-4%29%5E2-4%281%29%28-32%29+%29%29%2F%282%281%29%29\" Plug in \"a=1\", \"b=-4\", and \"c=-32\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B-+sqrt%28+%28-4%29%5E2-4%281%29%28-32%29+%29%29%2F%282%281%29%29\" Negate \"-4\" to get \"4\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B-+sqrt%28+16-4%281%29%28-32%29+%29%29%2F%282%281%29%29\" Square \"-4\" to get \"16\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B-+sqrt%28+16--128+%29%29%2F%282%281%29%29\" Multiply \"4%281%29%28-32%29\" to get \"-128\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B-+sqrt%28+16%2B128+%29%29%2F%282%281%29%29\" Rewrite \"sqrt%2816--128%29\" as \"sqrt%2816%2B128%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B-+sqrt%28+144+%29%29%2F%282%281%29%29\" Add \"16\" to \"128\" to get \"144\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B-+sqrt%28+144+%29%29%2F%282%29\" Multiply \"2\" and \"1\" to get \"2\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B-+12%29%2F%282%29\" Take the square root of \"144\" to get \"12\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B+12%29%2F%282%29\" or \"x+=+%284+-+12%29%2F%282%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2816%29%2F%282%29\" or \"x+=++%28-8%29%2F%282%29\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+8\" or \"x+=+-4\" Simplify. \r
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\n" ); document.write( "\n" ); document.write( "So the answers are \"x+=+8\" or \"x+=+-4\" \r
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\n" ); document.write( "\n" ); document.write( "This means that the x-intercepts are (8,0) and (-4,0)
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