Question

Which of the following is the general term for the sequence a, -a, a, -a, . . .?

a(-1)n+ 1
(-a)n
(-1)an+ 1

Answer 1

\[ (-1)^{n+1} a\]

Answer 2

put the value of n=1,2,3,4,... and see what you get.

Answer 3

Yeah! That makes sense

Answer 4

Is it the first or third option though?

Answer 5

@experimentX

Answer 6

come back

Answer 7

What's the difference between the first and third option?

Answer 8

they are completely different. put the values of n in the third series.