Question

Find an explicit rule for the nth term of the sequence.

-4, -8, -16, -32, ...

Answer 1

@UnkleRhaukus @aaronq

Answer 2

@ParthKohli

Answer 3

see any pattern ?

Answer 4

it multiplies by 2 after each number in the sequence

Answer 5

exactly ! so can you write an explicit rule for getting "nth" term ?

Answer 6

2 x -4^n ?

Answer 7

1st term = -4*2^0
2nd term = -4*2^1
3rd term = -4*2^2
...
nth term = ?

Answer 8

an = -4*2^n

Answer 9

Very close !!
plugin n =1, do u really get 1st term ?

Answer 10

oh, no

an = -4*2^n-1 ?

Answer 11

Yes :)

Answer 12

thanks ganshie!

Answer 13

\[\large a_n = -4*2^{n-1}\]