Question

Find an equation for the nth term of the sequence.

-3, -12, -48, -192, ..

Answer 1

is there a common ratio or a common difference? this would be one of the first things I look for.

Answer 2

common difference: 4

Answer 3

a common different is 4?
but -12-(-3) isn't 4

Answer 4

do you mean common ratio
-12/-3 is 4

Answer 5

since it has a common ratio it is a geometric sequence

Answer 6

the first term is -3
and the common ratio is 4
you have all you need to setup the formula for the nth term in the sequence

Answer 7

\[a_n=a_1 r ^{n-1} \text{ for integer } n \ge 2 \]

Answer 8

a_n = -3 * 4^n-1

Answer 9

\[a_n=-3 \cdot 4^{n-1}\]
is right