Respuesta :

Answer:

[tex]a_2=6[/tex]

Step-by-step explanation:

Geometric sequence general formula:  [tex]a_n=ar^{n-1}[/tex]

Given:

  • [tex]a_1=2[/tex]
  • [tex]a_3=18[/tex]
  • [tex]a_5=162[/tex]

Therefore,

[tex]a_1=2 \implies a=2[/tex]

[tex]a_3=2 \cdot r^2=18[/tex]

[tex]a_5=2 \cdot r^4=162[/tex]

To find common ratio r, divide 5th and 3rd terms:

[tex]\dfrac{a_5}{a_3}=\dfrac{2 \cdot r^4}{2 \cdot r^2}=\dfrac{162}{18}[/tex]

[tex]\implies r^2=9[/tex]

[tex]\implies r=\sqrt{9}=3[/tex]

Therefore, geometric sequence formula:  [tex]a_n=2 \cdot 9^{n-1}[/tex]

So second term of sequence:

[tex]\implies a_2=2 \cdot 3^{2-1}=6[/tex]