document.write( "Question 1209600: What is the domain of the function f(x) = sqrt(5 - 8x + x^2)? \n" ); document.write( "

Algebra.Com's Answer #849655 by mccravyedwin(408) $\"\"$ $\"About$

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document.write( "The graph of f(x) is in red below.\r\n" );
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document.write( "Let's look at the related graph in green, g(x), which\r\n" );
document.write( "equals what's under the square root radical:\r\n" );
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document.write( "As we see, f(x) stops when it gets to the leftmost x-intercept of g(x)\r\n" );
document.write( "and begins again at the rightmost x-intercept of of g(x).\r\n" );
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document.write( "The domain of f(x) INCLUDES both x-intercepts of g(x)\r\n" );
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document.write( "So we find the two x-intercepts of \r\n" );
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document.write( "which doesn't factor (which shows that the problem-maker is stupid) \r\n" );
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document.write( "So we stop and turn our attention away from what we're doing while we go \r\n" );
document.write( "over to the quadratic formula and solve it, and hope we can remember what \r\n" );
document.write( "we were doing before the stupid problem-maker made us stop and do that.\r\n" );
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document.write( "So the domain of f(x) is\r\n" );
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document.write( "We use \" ] \" and \" [ \" to show that the domain INCLUDES those values. \r\n" );
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document.write( "Edwin

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