Question

12. The sum of the series 1 ,-1 ,1 ,-1 ,1...... to 100 terms is equal to​

Answer 1

⇒Now this series has 3solutions. The first one is (1–1) +(1–1)+(1–1) so on till infinity if there are a even no of one's it becomes zero if there are a odd no of one's it becomes 1. But also you see this is also a infinite GP series with a=1,a common ratio of -1 so the formula is a/1-r=1/1–(-1)=1/2

Answer 2

Answer:

0

Step-by-step explanation:

a=1-1     d=(1-1)-(1-1) =0

n=100/2=50

sum= 50[2(1-1)+99(0)]

       =50*0

       =0