Question

What is the fourth term of the sequence? a1 = m an = 2an-1

Answer 1

a2=2a1=2m; a3=2a2=4m; a4=2a3=8m.

Answer 2

Fourth term of the sequence is 8m

Explanation:

Given: Sequence
`a_1=m \ and\ a_n=2a_(n-1)`

We have to find the fourth term of the given sequence.

Consider the given sequence
`a_n=2a_(n-1)`

Forth term will be
`a_4=2a_3`....(1)

We find third term first

`a_3=2a_2`...(2)

Also, given
`a_1=m`

and
`a_2=2a_1=2m` .....(3)

Put (3) in (2), we get,

`a_3=2(2m)=4m`...(4)

Put (4) in (1) , we get,

`a_4=2a_3=2(4m)=8m`

Thus, Fourth term of the sequence is 8m