I understand what Riemann sums are I really just know how to do these problems. I could really use a lot of help. I would appreciate a full explanation too because I am not just looking for the answer. I would really like to know what is going on in these two problems. I am not very good at Calculus, in fact I am terrible at it, but i am still determined to learn what I can. I really just need for someone to give me a helping hand with these problems because I just cannot figure them out. I understand the rules of this forum, but I cannot post any work because I really don't understand what to do. Please take pity on me. I will understand if you don't since these are the rules of your site, but I really am trying to learn and you all seem to give good information. So I am begging PLEASE HELP ME!