How do you write the first five terms of the geometric sequence $a_1=2, r=3$ ?

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Answer 1 · 2017-02-16T14:38:08

First five terms of geometric sequence are ${2,6,18,54,162}$

In a geometric sequence if $a_1$ is the first term and common ratio is $r$ ,

then the $n^(th)$ term $a_n$ is given by $a_n=a_1r^((n-1))$

Here $a_1=2$ and $r=3$

hence $a_2=2xx3^((2-1))=2xx3^1=2xx3=6$ ,

$a_3=2xx3^((3-1))=2xx3^2=2xx9=18$ ,

$a_4=2xx3^((4-1))=2xx3^3=2xx27=54$ ,

$a_5=2xx3^((5-1))=2xx3^4=2xx81=162$ .

Hence first five terms of geometric sequence are ${2,6,18,54,162}$

How do you write the first five terms of the geometric sequence a_1=2, r=3a_1=2, r=3?