Question

3. Find the sum of the following series:-
S=1/2-2/3+3/4-4/5+………..up to n terms

Answer 1

Explanation:

1st term = 1/2

2nd term = - 2/3

3rd term = 3/4

4th term = - 4/5

.

.

Nthe term = ((-1)N) * (N / (N + 1))

Therefore:

Nth term of the series

\frac{1}{2} - \frac{2}{3} + \frac{3}{4} - \frac{4}{5} + ... = (-1)^{N}\times \frac{N}{N+1}