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For the function f(x)=2/1+2x find f-1(x)

User Kike
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1 Answer

20 votes
20 votes

Starting with the expression:


f(x)=(2)/(1+2x)

Substitute f(x)=y and isolate x:


\begin{gathered} y=(2)/(1+2x) \\ \Rightarrow1+2x=(2)/(y) \\ \Rightarrow2x=(2)/(y)-1 \\ \Rightarrow x=(1)/(y)-(1)/(2) \end{gathered}

Swap x for y and vice versa:


y=(1)/(x)-(1)/(2)

Set y=f^{-1}(x):


f^(-1)(x)=(1)/(x)-(1)/(2)

User Johann Oskarsson
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