I'm struggling in question 7,9, and 13 in this exercise. I already have the answer provided from the book but I wonder the process to get that solution. I also struggling to graph the series in section b. Please help me, thank you so much!

In Exercises 7 - 14, a series an is given. (a) Give the first 5 partial sums of the series. (b) Give a graph of the first 5 terms of an and S, on the same axes. 0O 7. ( -1 ) n n n = 1 8. 1 2 iM 8 in8 9 . COs( Tn) 10. n 11. n! iMo iMo iMo iM8 12. 30 9 n 13. 10 14. 10 n=1Section 8.2 1. Answers will vary. 3. One sequence is the sequence of terms { an }. The other is the sequence of nth partial sums, {Sn} = {Et-a;}. 5. F 7 , (a) -1, -7 7 47 12 ' 60 (b) Plot omitted 9 . (a) -1, 0, -1,0, -1 (b) Plot omitted 11. 3 5 41 103 (a) 1, 2' 3' 24' 60 (b) Plot omitted 13. (a) -0.9, -0.09, -0.819, -0.1629, -0.75339