Respuesta :

Answer:

The first four terms are 3,9,27,81

Step-by-step explanation:

Step :-1

Given first term of sequence is [tex]a_{1} = 3[/tex]

Given 'n' t h term is [tex]a_{n} = 3 a_{n-1}[/tex]  .............(1)

here we put  n = 2 in equation (1)

[tex]a_{2} = 3a_{2-1}[/tex]

[tex]a_{2} = 3 a_{1}[/tex]    ..............2

put [tex]a_{1} = 3[/tex]      in equation (2)

[tex]a_{2} = 3(3)[/tex]  

[tex]a_{2} = 9[/tex]

put n=3 in equation (1)

[tex]a_{3} = 3 a_{3-1}[/tex]

[tex]a_{3} = 3a_{2}[/tex]

[tex]a_{3} = 3 (9) = 27[/tex]

put n= 4 in equation (1)

[tex]a_{4} = 3 a_{4-1}[/tex]

[tex]a_{4} = 3 a_{3}[/tex]

[tex]a_{4} = 3(27) = 81[/tex]

The first four terms of the sequence is

3 , 9, 27 , 81 ....this is geometric sequence

a =3 and ratio term is r =3