document.write( "Question 1183953: Find the domain and range of the function\r
\n" ); document.write( "\n" ); document.write( "f(x) = (x^2 + 1)/( 4x^2 - 8x + 3).
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Algebra.Com's Answer #814466 by MathLover1(20850)\"\" \"About 
You can put this solution on YOUR website!
\r
\n" ); document.write( "\n" ); document.write( "\"f%28x%29+=+%28x%5E2+%2B+1%29%2F%28+4x%5E2+-+8x+%2B+3%29\"\r
\n" ); document.write( "\n" ); document.write( "domain:\r
\n" ); document.write( "\n" ); document.write( "exclude \"x\" that makes denominator equal to zero\r
\n" ); document.write( "\n" ); document.write( "\"4x%5E2+-+8x+%2B+3=0+\".......use quadratic formula\r
\n" ); document.write( "\n" ); document.write( "\"x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F2a\"\r
\n" ); document.write( "\n" ); document.write( "\"x=%28-%28-8%29%2B-sqrt%28%28-8%29%5E2-4%2A4%2A3%29%29%2F%282%2A4%29\"\r
\n" ); document.write( "\n" ); document.write( "\"x=%288%2B-sqrt%2864-48%29%29%2F8\"\r
\n" ); document.write( "\n" ); document.write( "\"x=%288%2B-sqrt%2816%29%29%2F8\"\r
\n" ); document.write( "\n" ); document.write( "\"x=%288%2B-4%29%2F8\"\r
\n" ); document.write( "\n" ); document.write( "\"x=%282%2B-1%29%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "solutions\r
\n" ); document.write( "\n" ); document.write( "\"x=%282-1%29%2F2\"=>\"x=+1%2F2\"
\n" ); document.write( "\"x=%282%2B1%29%2F2\"=>\"x=+3%2F2\"\r
\n" ); document.write( "\n" ); document.write( "so, domain is:\r
\n" ); document.write( "\n" ); document.write( "{ \"x\" element \"R\" :\"+x%3C%3E1%2F2\" ,\"x%3C%3E3%2F2+\", \"x%3E3%2F2\" }
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\n" ); document.write( "Interval notation:\r
\n" ); document.write( "\n" ); document.write( "(\"-infinity\" , \"1%2F2\" ) U ( \"1%2F2\", \"3%2F2\" ) U ( \"3%2F2\", \"infinity+\")\r
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\n" ); document.write( "\n" ); document.write( "range:\r
\n" ); document.write( "\n" ); document.write( "the range is the set of y for which the discriminant is greater or equal to zero \r
\n" ); document.write( "\n" ); document.write( "\"y=+%28x%5E2+%2B+1%29%2F%28+4x%5E2+-+8x+%2B+3%29\"\r
\n" ); document.write( "\n" ); document.write( "\"y%28+4x%5E2-8x+%2B+3%29=+x%5E2+%2B+1\"\r
\n" ); document.write( "\n" ); document.write( "\"4yx%5E2-x%5E2-+8yx+%2B+3y-1=0\"\r
\n" ); document.write( "\n" ); document.write( "\"%284y-1%29x%5E2-+8yx+%2B+%283y-1%29=0\"\r
\n" ); document.write( "\n" ); document.write( "->discriminant >=0\r
\n" ); document.write( "\n" ); document.write( "\"b%5E2-4ac=%28-8y%29%5E2-4%284y-1%29%283y-1%29\"\r
\n" ); document.write( "\n" ); document.write( "\"b%5E2-4ac=64y%5E2-48+y%5E2+%2B+28+y+-+4\"\r
\n" ); document.write( "\n" ); document.write( "\"b%5E2-4ac=16y%5E2+%2B+28+y+-+4\"\r
\n" ); document.write( "\n" ); document.write( "\"16y%5E2+%2B+28+y+-+4+%3E=0\" .......divide by \"4\"\r
\n" ); document.write( "\n" ); document.write( "\"4y%5E2+%2B+7y+-+1+%3E=0\"\r
\n" ); document.write( "\n" ); document.write( "use quadratic formula\r
\n" ); document.write( "\n" ); document.write( "\"y=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29\"\r
\n" ); document.write( "\n" ); document.write( "\"y=%28-7%2B-sqrt%287%5E2-4%2A4%28-1%29%29%29%2F%282%2A4%29\"\r
\n" ); document.write( "\n" ); document.write( "\"y=%28-7%2B-sqrt%2849%2B16%29%29%2F8\"\r
\n" ); document.write( "\n" ); document.write( "\"y=%28-7%2B-sqrt%2865%29%29%2F8\"\r
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\n" ); document.write( "\n" ); document.write( "solutions\r
\n" ); document.write( "\n" ); document.write( "\"%28sqrt%2865%29-7%29%2F8%3E=0+\"\r
\n" ); document.write( "\n" ); document.write( "\"%28-7-sqrt%2865%29%29%2F8%3E=0+\"\r
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\n" ); document.write( "\n" ); document.write( "range is:\r
\n" ); document.write( "\n" ); document.write( "{ \"f+%28x+%29\" element \"R\" : \"f+%28x+%29+%3C=%28-7-sqrt%2865%29%29%2F8\" or \"+f+%28x+%29+%3E=%28sqrt%2865%29-7%29%2F8\" }\r
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