Question

2. Find 10" term of the sequence defined by a. =(-1) ×5"
​

Answer 1

Answer:

We have, a

n

=(−1)

n−1

.2

n

Putting n=1,2,3,4 and 5, we get

a

1

=(−1)

1−1

×2

1

=(−1)

0

×2=2

a

2

=(−1)

2−1

×2

2

=(−1)

1

×4=−4

a

3

=(−1)

3−1

×2

3

=(−1)

2

×8=8

a

4

=(−1)

4−1

×2

4

=(−1)

3

×16=−16

and, a

5

=(−1)

5−1

×2

5

=(−1)

4

×32=32

The first five terms are 2,−4,8,−16,32