document.write( "Question 1073529: Given that g(x)=4/x , x is not equal to 0 and fg(x)=2x+3 find the function f. \n" ); document.write( "
Algebra.Com's Answer #688337 by josgarithmetic(39623)\"\" \"About 
You can put this solution on YOUR website!
That 2x+3 is the PRODUCT of the functions f and g.\r
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\n" ); document.write( "\n" ); document.write( "\"fg%28x%29=f%28x%29g%28x%29=f%28x%29%2A%284%2Fx%29=2x%2B3\"\r
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\n" ); document.write( "\n" ); document.write( "\"f%28x%29%2A%284%2Fx%29=2x%2B3\"-------solve this for f(x).\r
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\n" ); document.write( "You want really the composition \"f%28g%28x%29%29=2x%2B3\".
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\n" ); document.write( "\n" ); document.write( "Given \"g%28x%29=4%2Fx\" and the FUNCTION COMPOSITION \"f%28g%28x%29%29=2x%2B3\", find the function f(x).\r
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\n" ); document.write( "\n" ); document.write( "g(x) is used as input into f(x) and the expression for the composition is shown, 2x+3.
\n" ); document.write( "You are given g(x), so substitute for its expression.\r
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\n" ); document.write( "\n" ); document.write( "\"f%284%2Fx%29=2x%2B3\"\r
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\n" ); document.write( "\n" ); document.write( "The input indicated on the left side is \"4%2Fx\", but you want to have an input of x, because you want to find f(x).
\n" ); document.write( "What number, r, can you put into 4/x so that the result becomes x?
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\n" ); document.write( "\"4%2Fr=x\"\r
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\n" ); document.write( "\n" ); document.write( "\"%284%2Fr%29%2Ar=x%2Ar\"\r
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\n" ); document.write( "\n" ); document.write( "\"4=r%2Ax\"\r
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\n" ); document.write( "\n" ); document.write( "\"rx=4\"\r
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\n" ); document.write( "\n" ); document.write( "\"rx%281%2Fx%29=4%281%2Fx%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"highlight_green%28r=4%2Fx%29\"\r
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\n" ); document.write( "\n" ); document.write( "Now you want to replace x in the function \"f%284%2Fx%29=2x%2B3\" with \"r=4%2Fx\".
\n" ); document.write( "These must be done to both sides of the function equation.
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\n" ); document.write( "\"f%284%2Fr%29=2r%2B3\"\r
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\n" ); document.write( "\n" ); document.write( "\"f%284%2F%284%2Fx%29%29=2%284%2Fx%29%2B3\"\r
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\n" ); document.write( "\n" ); document.write( "\"f%28%284%2F4%29x%29=8%2Fx%2B3\"\r
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\n" ); document.write( "\n" ); document.write( "\"highlight%28f%28x%29=8%2Fx%2B3%29\",
\n" ); document.write( "The function f(x) is now found.
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