u/MrClassiano

So i was doing this problem set from MIT OCW 18.01 (Single Variable Calc)
and P2, part C really perplexed me, cuz what function am i supposed to differentiate? f(x) or g(x) or the equation
I did some calculation that f(x) was equal to (ln 4)/2 😭. attaching both my working and the problem here

I think my main doubt lies whether you could do the cancelling i did on STAR step. and if you can’t do that
i’d like to know why not exactly and how will we solve this problem. THXXXX