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

Question

2421 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-02-21T10:32:42

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

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

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

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

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

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

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