The first five terms of the geometric series is : -2, -6, -18, -54, -162.
Given : [tex]a_{5} = -162[/tex]
[tex]a_{2} = -6[/tex]
We know G.P. series always increases in the form [tex]a.r^{n-1}[/tex]
Similarly, [tex]a_{5} = a.r^{5-1} = a.r^{4} = -162[/tex]
[tex]a_{2} = a.r^{2-1} = a.r = -6[/tex]
Now, [tex]\frac{a_{5} }{a_{2} } = \frac{a.r^{4} }{a.r^{1} } = r^{4-1}[/tex]
[tex]r^{3} = \frac{-162}{-6} = 27[/tex]
[tex]r = \sqrt[3]{27} = 3[/tex]
Now,
[tex]a_{2} = a.r = -6\\a.(3) = -6\\a = -2[/tex]
The first 5 terms are : [tex]a, a.r, a.r^{2} , a.r^{3} , a.r^{4}[/tex]
[tex]-2 , (-2).3 , (-2).3^{2} , (-2).3^{3} , (-2).3^{4}[/tex]
Therefore, The first 5 terms are : -2, -6, -18, -54, -162.
To learn more about G.P. series, refer to :
https://brainly.com/question/24643676
#SPJ2
