thank you so much atheist. i have done the first part. and for the second part i can do by myself but teacher wants it from mathematica. In normaly they must teach but they showed just a little part of mathematica. and they want the answers in printouts tomorrow. if they accept of course i can write by hand, but the homework is about mathematica if you can help for the second one too,i will be glad. i donno any function or anything else in this program. because my depertman is not mathematics lol. if you can write the full formulas or anything that can help me, i would be glad.