Math Problem Statement

Let's first look at the equation you have: a n

2 a n − 1 + a n − 2 − 2 a n − 3 a n ​ =2a n−1 ​ +a n−2 ​ −2a n−3 ​

You mentioned some values: a 0

3 a 0 ​ =3 a 1

6 a 1 ​ =6 a 2

0 a 2 ​ =0

Solution

Let's break down the equation you provided:

an=2an1+an22an3a_n = 2a_{n-1} + a_{n-2} - 2a_{n-3}

This is a recursive relation, which defines each term ana_n in terms of the previous three terms in the sequence: an1,an2,a_{n-1}, a_{n-2}, and an3a_{n-3}.

You also provided initial conditions:

  • a0=3a_0 = 3
  • a1=6a_1 = 6
  • a2=0a_2 = 0

To find further terms in the sequence (e.g., a3,a4a_3, a_4, etc.), we can apply the recursive relation step by step.

Let's find a3a_3:

Using the equation an=2an1+an22an3a_n = 2a_{n-1} + a_{n-2} - 2a_{n-3} for n=3n = 3:

a3=2a2+a12a0a_3 = 2a_2 + a_1 - 2a_0

Substituting the known values a2=0a_2 = 0, a1=6a_1 = 6, and a0=3a_0 = 3:

a3=2(0)+62(3)a_3 = 2(0) + 6 - 2(3)

a3=66=0a_3 = 6 - 6 = 0

So, a3=0a_3 = 0.

Let's find a4a_4:

Now, for n=4n = 4:

a4=2a3+a22a1a_4 = 2a_3 + a_2 - 2a_1

Substitute the known values a3=0a_3 = 0, a2=0a_2 = 0, and a1=6a_1 = 6:

a4=2(0)+02(6)a_4 = 2(0) + 0 - 2(6)

a4=012=12a_4 = 0 - 12 = -12

So, a4=12a_4 = -12.

Let's find a5a_5:

Now, for n=5n = 5:

a5=2a4+a32a2a_5 = 2a_4 + a_3 - 2a_2

Substitute the known values a4=12a_4 = -12, a3=0a_3 = 0, and a2=0a_2 = 0:

a5=2(12)+02(0)a_5 = 2(-12) + 0 - 2(0)

a5=24+0=24a_5 = -24 + 0 = -24

So, a5=24a_5 = -24.


Would you like to see more terms of the sequence or a deeper explanation?

Related questions:

  1. How do we determine the general form of a recursive sequence?
  2. Can we find an explicit formula for this recursive sequence?
  3. How does changing initial conditions affect the sequence?
  4. How are recursive sequences used in real-world problems?
  5. What happens if we add more terms to the recursive equation?

Tip:

When working with recursive relations, having clear initial conditions is essential to generating the correct sequence. Always verify each step carefully to avoid errors when calculating subsequent terms!

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Math Problem Analysis

Mathematical Concepts

Sequences
Recurrence Relations

Formulas

a_n = 2a_{n-1} + a_{n-2} - 2a_{n-3}

Theorems

Recurrence Relation

Suitable Grade Level

Grades 10-12