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If f(x) = x+34x−5,g(x)=3+5x4x−1 then verify that (fog)(x) = x. - Mathematics and Statistics

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Question

If f(x) = `(x+3)/(4x−5) , "g"(x) = (3+5x)/(4x−1)` then verify that `("fog") (x)` = x.

Sum
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Solution

f(x) = `(x+3)/(4x−5) , "g"(x) = (3+5x)/(4x−1)`

`("fog")(x) = "f(g"(x))`

= f`((3+5x)/(4x-1))`

=`((3+5x)/(4x-1)+3)/(4((3+5x)/(4x-1))-5`

= `(3+5x+12x - 3)/(12+20x-20x+5)`

= `(17x)/17`

= x

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Chapter 2: Functions - Miscellaneous Exercise 2 [Page 32]

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