Question

How do you write an equation for the nth term of the geometric sequence `4,-12,36,...`?

Answer 1

`T_n=-4/3 (-3)^n`

Explanation:

`T_n = ar^(n-1)` where `T_n` = nth term, a = first term and r = common ratio.

`a = 4` and `r=-12/4 =-3`,

`T_n =4(-3)^(n-1)`

`T_n=4(-3)^n*(-3)^-1 =4(-1/3)(-3)^n`

`T_n=-4/3 (-3)^n`