What is the function inverse of f(x)=50,000(.8)^x

Verified Answer :

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Answer:

\(f^{-1}(x)=\frac{\log(\frac{x}{50000})}{\log 0.8}\)

Step-by-step explanation:

Given : The function \(f(x)=50000(0.8)^x\)

To find : The inverse of the given function?

Solution :

We write the given function as,

\(y=50000(0.8)^x\)

Taking log both side,

\(\log y=\log 50000+\log (0.8)^x\)

Apply logarithmic property, \(\log a^x=x\log a\)

\(\log y=\log 50000+x\log 0.8\)

\(x=\frac{\log y-\log 50000}{\log 0.8}\)

Now, interchange the value of x and y

\(y=\frac{\log x-\log 50000}{\log 0.8}\)

\(f^{-1}(x)=\frac{\log x-\log 50000}{\log 0.8}\)

\(f^{-1}(x)=\frac{\log(\frac{x}{50000})}{\log 0.8}\)