 Hi and welcome to the session I am Kanika and I am going to help you to solve the following question. The question says write the first five terms of each of the sequences in exercises 11 to 13 and obtain the corresponding series. 12th part is A1 is equal to minus 1, A n is equal to A n minus 1 upon n, n is greater than equal to 2. Before solving this question we should know that if A1, A2 and so on A n is the given sequence then the expression A1 plus A2 plus A n plus so on is the series associated with the given sequence. Let's now begin the distribution. The question we are given the first term of the sequence that is A1 is equal to minus 1. As we are given the first term of the sequence we have to only find the next four terms of the sequence by using the relation A n is equal to A n minus 1 upon n when n is greater than equal to 2. Since we need to find the second, third, fourth and fifth term therefore we will put n as 2, 3, 4 and 5. By substituting n as 2 in this relation we get A2 is equal to A2 minus 1 upon 2 this is equal to A1 by 2 and A1 is equal to minus 1 so this is equal to minus 1 by 2. By substituting n as 3 we get A3 is equal to A3 minus 1 by 3 this is equal to A2 by 3 and A2 is equal to minus 1 by 2 so we have minus 1 by 2 into 3 and this is equal to minus 1 by 6. By substituting n as 4 we get A4 is equal to A4 minus 1 upon 4 this is equal to A3 by 4 now A3 is equal to minus 1 by 6 so we have minus 1 by 6 into 4 and this is equal to minus 1 by 24. By substituting n as 5 we get A5 is equal to A5 minus 1 by 5 and this is equal to A4 by 5 A4 is equal to minus 1 by 24 so we have minus 1 by 24 into 5 and this is equal to minus 1 by 20. Hence the required first five terms of the sequence are minus 1 minus 1 by 2 minus 1 by 6 minus 1 by 24 and minus 1 by 20. And the corresponding series is minus 1 plus minus 1 by 2 plus minus 1 by 6 plus minus 1 by doing 4 plus minus 1 by 120 plus so on. This is our required answer so this completes the session. Bye and take care.