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If a_1 =2 and a_n = 3a_n-1 - 2 then find the value of a_5.

2 Answers

4 votes

Answer:

and

We need to find common difference, in order for us to do that, Let try to find a2.

Remebr a1=2

so a2=

so a2=4.

This means the common difference is 2 because a1 is 2 and a2 is 4.

Now, we use arithmetic formula to find a5

Where a is the inital term, a1

D is common difference and n is the term we trying to find

So we get

So

a_5=10

Explanation:

User Mudit Saklani
by
7.7k points
9 votes

Explanation:

We know that


a _(1) = 2

and


a _(n) = 3a _(n - 1) - 2

We need to find common difference, in order for us to do that, Let try to find a2.


a _(2) = 3a _(2 - 1) - 2


a _(2) = 3 a_(1) - 2

Remebr a1=2


a _2{} = 3(2) - 2

so a2=


6 - 2 = 4

so a2=4.

This means the common difference is 2 because a1 is 2 and a2 is 4.

Now, we use arithmetic formula to find a5


a + d(n - 1)

Where a is the inital term, a1

D is common difference and n is the term we trying to find

So we get


2 + 2(5 - 1) = 2 + 2(4) = 10

So

a_5=10

User Jinghui Niu
by
8.1k points