I made a mistake in my previous post.I need help with the integral

very lengthy question... assuming you are not a mathematitian and are studying for marks, here is a tip, if you see this type of long question, quickly skip it, it doesnt matter if you can do difficult question or not, the bitter truth is, marks is all that matters now... you will get to show off your brains later ;) cheers :)

P.S. sorry for not answering your question