Hi, got a question in my book, but couldnt find the way to solve it.
http://www.flickr.com/photos/84336100@N02/7723429060/in/photostream
For the second one, i can do part a and b by myself, but i dun know how to do part c by using the answer in part b.
if you could help me by showing the working that would be much appreciated
Thanks