Andrew explains this GMAT Prep question:
For which of the following functions is f(a+b) = f(b) + f(a) for all positive numbers a and b?
You can find an in depth Atlantic GMAT blog post here: https://atlanticgmat.com/for-which-of-the-following-functions-is-fab-fb-fa-for-all-positive-numbers-a-and-b/
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