# How do you write the first five terms of the geometric sequence #a_1=5, a_(k+1)=-2a_k# and determine the common ratio and write the nth term of the sequence as a function of n?

##### 2 Answers

Sep 29, 2017

first 5 terms

common ratio

nth term

#### Explanation:

first 5 terms

common ratio

is

nth term of any Gp

Oct 8, 2017

so,

=>

Also,

i.e.

so, our terms are

Hence, 1st term 5 and common ratio -2

Now, nth term is

i.e.

or,

With n = 7 we have:

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