This should be an easy one for most people, I guess. In trying to differentiate the given expression, I used the chain rule twice and got an answer that looks almost correct; however, according to the answer sheet provided with the problems, as well as an online derivative calculator, then answer should not be negative. Unfortunately, my answer ends up with a '-' sign in front of it; otherwise, everything else is in accordance with the previously-stated, given correct answers. "Close, but no cigar," as the saying goes.

Where did I go wrong? I have looked at it and looked at it, but I just can't see what I did wrong. Of course, I'm looking at it with the same faulty reasoning as what I had when I did the problem, so I'm in need of a fresh way to look at it.

I have attached a photo of my faulty solution; hope it is clear enough to read. I have never tried to attach a file on this forum, so I don't really know what the required parameters are for such a pic.

Any help would be much appreciated!

Where did I go wrong? I have looked at it and looked at it, but I just can't see what I did wrong. Of course, I'm looking at it with the same faulty reasoning as what I had when I did the problem, so I'm in need of a fresh way to look at it.

I have attached a photo of my faulty solution; hope it is clear enough to read. I have never tried to attach a file on this forum, so I don't really know what the required parameters are for such a pic.

Any help would be much appreciated!