Question 591284
A)

Assuming the base is 10, the inverse is <img src="http://latex.codecogs.com/gif.latex?\large f^{-1}(x)=10^{x}" />. This is because the two effectively 'undo' each other


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B)

In general, the inverse of <img src="http://latex.codecogs.com/gif.latex?\large f(x) = b^{x}" /> is <img src="http://latex.codecogs.com/gif.latex?\large f^{-1}(x) = \log_{b}(x)" />


In this case, b = 7. So the inverse function is  <img src="http://latex.codecogs.com/gif.latex?\large f^{-1}(x) = \log_{7}(x)" />