can someone tell me the nth term in the sequence 1, -1, 1, -1?

Question

also -1, 1, -1, 1

Answer 1

Common ratio = -1

first term = -1

nth term = -1(-1)^(n-1)

Another way of writing this is...

-(-1)^(n-1)

Answer 2

For the first case
(-1)^(n-1)

Test:
n=1 then n-1=0 and -1^0 =1
n=2 then n-1=1 and -1^1 = -1
n=3 then n-1=2 and -1^2 = 1

etc.

For the second case -1^n

Answer 3

if n is even then its -1 or else if n is odd then its 1..Considering the series consists of terms numbered from 1 to n and not 0 to n-1

Answer 4

For 1,-1,1,-1-----
the nth term =1(for n=odd)
& =-1(for n=even)
& reverse for -1,1,-1,1-------ans

Answer 5

or write it as a_n = (-1)^n for n > 0