# Solving for unknown, trouble with $\ln$ and $\exp$

Having some trouble understanding $\ln$ and $\exp$ rules and what to do in this situation. Perhaps it has just been a very long day...

$$\hat{Y} = \exp \left[\left(\hat{\beta_0} + \sum_i \hat{\beta_i}{x_i}\right)\space A' \right]$$

Solving for $A'$.

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Are $\hat{Y}$ and $A'$ matrices or real numbers ? –  vanna Aug 3 '12 at 17:46

$\ln$ and $\exp$ are inverse of each others. So if $$y = \exp(x)$$ this means $$\ln(y) = \color{red}{\ln(\exp}(x)) = x.$$ In your case take $\ln$ of both sides. Can you take it from here?