Your attachment is essentially unreadable. Why not adhere to PF standards and just type out the problem and your proposed solution?please check the attachment below. The question and the attempted solution is found there. Thanks a lot for your help in advance.
The ##X## is most likely an argument of the function ##\sin##, that is, it should be inside the brackets. Why are you studying quantum mechanics without doing calculus first? You should definitely study calculus before. This is the simplest math you'll encounter.Hey Ray, please look at the updated attachment below. I have tried to edit the old one but dont see any button that would allow me do so. Thanks so much for your help in advance! :)