Find the first three terms of the sequence described by the following recursive formula:
an = 3an – 1 + 2 where a4 = 20

a1=
a2=
a3=

Respuesta :

I think it would be these
1. -2/9
2. 4/3
3. 6

Answer:

a1= -2/9

a2= 4/3

a3= 6

Step-by-step explanation:

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

a_4= 20

lets plug in 4 for n

[tex]a_4 = 3a_{4 - 1} + 2[/tex]

[tex]20= 3a_3+ 2[/tex]

Subtract 2 from both sides and then divide by 3

18 = 3a_3

[tex]6=a_3[/tex]

lets plug in 3 for n and use a3=6 to find a2

[tex]a_3 = 3a_{3 - 1} + 2[/tex]

[tex]6= 3a_2+ 2[/tex]

Subtract 2 from both sides and then divide by 3

4 = 3a_2

[tex]\frac{4}{3}=a_2[/tex]

lets plug in 2 for n and find out a1

[tex]a_2 = 3a_{2 - 1} + 2[/tex]

[tex]\frac{4}{3}= 3a_1+ 2[/tex]

Subtract 2 from both sides and then divide by 3

[tex]\frac{-2}{3}= 3a_1[/tex]

[tex]\frac{-2}{9}=a_1[/tex]

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