(for copy-pasting into questions) What are your thoughts? What have you tried? Where are you stuck? You need to [provide context__http://meta.math.stackexchange.com/questions/9959/how-to-ask-a-good-question) for your question. Otherwise it just looks like you want somebody to do your homework for you; that's not what this site is for. If you add some appropriate context, we will be happy to help.