document.write( "Question 161482: CAN SOMEONE PLEASE HELP ME WITH THIS PROBLEM PLEASE:\r
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document.write( "Find the domain of the composite function f o g.\r
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document.write( "f(x) = 2 / x + 10 , g(x) = 60 / x \n" );
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Algebra.Com's Answer #118993 by gonzo(654)![]() ![]() ![]() You can put this solution on YOUR website! f(x) = 2/x + 10 \n" ); document.write( "i'll assume that means (2/x) + 10. \n" ); document.write( "hopefully that's right. \n" ); document.write( "if not, resubmit the question. \n" ); document.write( "g(x) = 60/x. \n" ); document.write( "----- \n" ); document.write( "i assume you are looking for f(g(x)). \n" ); document.write( "if that's what fog means then we're ok. \n" ); document.write( "i'll answer for that. \n" ); document.write( "resubmit the question if i got it wrong. \n" ); document.write( "----- \n" ); document.write( "g(x) = 60/x (given) \n" ); document.write( "f(x) = (2/x) + 10 (given) \n" ); document.write( "to solve for f(g(x)) you have to replace x with g(x). \n" ); document.write( "this is no different then solving for f(3). \n" ); document.write( "you replace x with 3. \n" ); document.write( "----- \n" ); document.write( "in this case you replace x with g(x) which means you replace \n" ); document.write( "x with (60/x) \n" ); document.write( "----- \n" ); document.write( "since f(x) = (2/x) + 10, then \n" ); document.write( " \n" ); document.write( "2/(60/x) is the same as (2*x)/60. \n" ); document.write( "you get that by multiplying the numerator and denominator by x. \n" ); document.write( "2*x/(60*x/x) = 2*x/60 since the x in the denominator cancels out. \n" ); document.write( "equation becomes \n" ); document.write( " \n" ); document.write( "this becomes \n" ); document.write( " \n" ); document.write( "----- \n" ); document.write( "the domain of f(x) would be all values of x except 0 since you can't divide by 0. \n" ); document.write( "----- \n" ); document.write( "the domain of g(x) would be the same, i.e. all values of x except 0 for the same reason. \n" ); document.write( "----- \n" ); document.write( "the domain of f(g(x)), however, would be all values of x since x is now in the numerator rather than the denominator. \n" ); document.write( " \n" ); document.write( " |