I'm currently learning how to differentiate equations using multiple rules.
I have the following problem
First, I tried to solve the problem without simplify the equation, here is my solution, which I checked against the answer provided and it is correct
Next, I tried to simplify the equation first before trying to find its derivative. But I got a different solution (which I think is wrong, but I have checked my logics multiple times and every step seem to be make sense, to me at least)
Could someone please point out where I got it wrong?