Write an explicit formula for the sequence 3,-9,27,-81

Question

asked May 3, 2019 10.2k views

1 Answer

Radovan Synek · Answer 1 · 2019-05-08T13:56:06+0000

The initial value is 3. The common ratio is -9/3 = -3. The general formula is
.. an = a1*r^(n-1)

So, for your values, ...
.. an = 3*(-3)^(n -1)