17.05.2023

write a recursive rule for the nth term of the sequence: (3.2, 4.7, 6.2.)

. 4

Faq

Mathematics
Step-by-step answer
P Answered by PhD

Step-by-step explanation:

{9, 14, 19, ...} so it looks like 5 is added to the previous term to get next

The recursive rule may be

a_{1} =9

a_{n} = a_{n-1} +5

The fith term is you find by writing the arithmetic sequence formula

a_{n} = a_{1} + (n-1) d , where d is how much you add

yet for the 5th term

a_{5} = a_{1} + (5-1)* 5

a_{5} = 9 +4*5 = 9+20 =29

Mathematics
Step-by-step answer
P Answered by PhD

Step-by-step explanation:

{9, 14, 19, ...} so it looks like 5 is added to the previous term to get next

The recursive rule may be

a_{1} =9

a_{n} = a_{n-1} +5

The fith term is you find by writing the arithmetic sequence formula

a_{n} = a_{1} + (n-1) d , where d is how much you add

yet for the 5th term

a_{5} = a_{1} + (5-1)* 5

a_{5} = 9 +4*5 = 9+20 =29

Mathematics
Step-by-step answer
P Answered by Master

Hello,

U_1=5\\U_{(n)}=4*U{(n-1)}

Mathematics
Step-by-step answer
P Answered by Specialist

b_n = \frac{2}{27} (9^n)

Step-by-step explanation:

Given

a_1=\frac{2}{3},\ a_n=3a_{n-1}.

Required

An explicit rule for b_1,\ b_2,\ b_3,\ \dots

Where b_1=a_1,\ b_2=a_3,\ b_3=a_5,\ \dots

We have:

a_1=\frac{2}{3},\ a_n=3a_{n-1}.

Calculate a2

a_2 = 3a_{2-1}

a_2 = 3a_1

a_2 = 3 * \frac{2}{3}

a_2 = 2

Calculate a3

a_3 = 3a_{3-1}

a_3 = 3a_2

a_3 = 3  *2

a_3 = 6

Calculate a4

a_4 = 3a_{4-1}

a_4 = 3a_3

a_4 = 3*6

a_4 = 18

Calculate a5

a_5 = 3a_{5-1}

a_5 = 3a_4

a_5 = 3*18

a_5 = 54

So:

b_1=a_1,\ b_2=a_3,\ b_3=a_5,\ \dots

a_1=\frac{2}{3}     a_3 = 6     a_5 = 54

The above sequence form a geometric sequence.

Calculate common ratio (r)

r = \frac{b_3}{b_2}

r = \frac{a_5}{a_3}

r = \frac{54}{6}

r = 9

So, the explicit formula is:

b_n = b_1 * r^{n-1

b_1=a_1, so:

b_n = a_1 * r^{n-1

a_1=\frac{2}{3}, so:

b_n = \frac{2}{3} * 9^{n-1

Split:

b_n = \frac{2}{3} * \frac{9^n}{9}

b_n = \frac{2}{3*9} (9^n)

b_n = \frac{2}{27} (9^n)

The explicit rule is: b_n = \frac{2}{27} (9^n)

Mathematics
Step-by-step answer
P Answered by Master

b_n = \frac{2}{27} (9^n)

Step-by-step explanation:

Given

a_1=\frac{2}{3},\ a_n=3a_{n-1}.

Required

An explicit rule for b_1,\ b_2,\ b_3,\ \dots

Where b_1=a_1,\ b_2=a_3,\ b_3=a_5,\ \dots

We have:

a_1=\frac{2}{3},\ a_n=3a_{n-1}.

Calculate a2

a_2 = 3a_{2-1}

a_2 = 3a_1

a_2 = 3 * \frac{2}{3}

a_2 = 2

Calculate a3

a_3 = 3a_{3-1}

a_3 = 3a_2

a_3 = 3  *2

a_3 = 6

Calculate a4

a_4 = 3a_{4-1}

a_4 = 3a_3

a_4 = 3*6

a_4 = 18

Calculate a5

a_5 = 3a_{5-1}

a_5 = 3a_4

a_5 = 3*18

a_5 = 54

So:

b_1=a_1,\ b_2=a_3,\ b_3=a_5,\ \dots

a_1=\frac{2}{3}     a_3 = 6     a_5 = 54

The above sequence form a geometric sequence.

Calculate common ratio (r)

r = \frac{b_3}{b_2}

r = \frac{a_5}{a_3}

r = \frac{54}{6}

r = 9

So, the explicit formula is:

b_n = b_1 * r^{n-1

b_1=a_1, so:

b_n = a_1 * r^{n-1

a_1=\frac{2}{3}, so:

b_n = \frac{2}{3} * 9^{n-1

Split:

b_n = \frac{2}{3} * \frac{9^n}{9}

b_n = \frac{2}{3*9} (9^n)

b_n = \frac{2}{27} (9^n)

The explicit rule is: b_n = \frac{2}{27} (9^n)

Mathematics
Step-by-step answer
P Answered by PhD

ANSWER

See explanation

EXPLANATION

Question 1:

The third term of the arithmetic sequence is :

14=a+2d...(1)

The twelveth term is

59=a+11d...(2)

Subtract equation (1) from (2)

45=9d

This implies that

d=5

a=14-2(5)=4

The explicit rule is;

a_{n}=4 + 5(n - 1)

a_{n}=4 + 5n -5

a_{n} = 5n -1

Recursive formula:

a_{n}=a_{n - 1} + 5

Question 2

The geometric sequence has the fourth term to be 2 and the common ratio to be r=⅓

This implies that,

a {( \frac{1}{3} })^{3}  = 2

This implies that,

\frac{a}{27}  = 2

a = 54

The explicit rule:

a_n=54 {( \frac{1}{3} })^{n - 1}

The recursive rule is

a_n=( \frac{1}{3} )a_{n-1}

where,

a_1 = 54

Mathematics
Step-by-step answer
P Answered by PhD

ANSWER

See explanation

EXPLANATION

Question 1:

The third term of the arithmetic sequence is :

14=a+2d...(1)

The twelveth term is

59=a+11d...(2)

Subtract equation (1) from (2)

45=9d

This implies that

d=5

a=14-2(5)=4

The explicit rule is;

a_{n}=4 + 5(n - 1)

a_{n}=4 + 5n -5

a_{n} = 5n -1

Recursive formula:

a_{n}=a_{n - 1} + 5

Question 2

The geometric sequence has the fourth term to be 2 and the common ratio to be r=⅓

This implies that,

a {( \frac{1}{3} })^{3}  = 2

This implies that,

\frac{a}{27}  = 2

a = 54

The explicit rule:

a_n=54 {( \frac{1}{3} })^{n - 1}

The recursive rule is

a_n=( \frac{1}{3} )a_{n-1}

where,

a_1 = 54

Mathematics
Step-by-step answer
P Answered by Specialist
recursive rule—a rule for generating terms of a sequence that depends on one or more previous terms of the sequence

iterative rule—rule that can be used to find the nth term of a sequence without calculating previous terms of the sequence, also called the Explicit Rule

model parameter—value that is held constant in a specific function, or model, while other variables might change

common difference—the constant d of the sequence.

arithmetic sequence—a sequence where the difference between consecutive terms is a constant

model variable—a variable that takes on different values in a specific function, or model, while other values are held constant

common ratio—the constant r of the sequence

sequence—a list of numbers, finite or infinite, that follow a particular pattern

terms of a sequence—the numbers in a sequence

geometric sequence—a sequence where the ratio between consecutive terms is a constant 

1. C     2. D     3.  I     4. G     5. E     6. J     7. H     8. A     9. B     10. F
Mathematics
Step-by-step answer
P Answered by Master
recursive rule—a rule for generating terms of a sequence that depends on one or more previous terms of the sequence

iterative rule—rule that can be used to find the nth term of a sequence without calculating previous terms of the sequence, also called the Explicit Rule

model parameter—value that is held constant in a specific function, or model, while other variables might change

common difference—the constant d of the sequence.

arithmetic sequence—a sequence where the difference between consecutive terms is a constant

model variable—a variable that takes on different values in a specific function, or model, while other values are held constant

common ratio—the constant r of the sequence

sequence—a list of numbers, finite or infinite, that follow a particular pattern

terms of a sequence—the numbers in a sequence

geometric sequence—a sequence where the ratio between consecutive terms is a constant 

1. C     2. D     3.  I     4. G     5. E     6. J     7. H     8. A     9. B     10. F
Mathematics
Step-by-step answer
P Answered by PhD

f(n) = f(n-1) + 8 for n  1

Step-by-step explanation:

Given

f(1) = 3 -- First Term

\frac{1}{2}d = 4 --- half common difference

Required

Find the recursive rule

First, we calculate the common difference

\frac{1}{2}d = 4

Multiply through by 2

2 * \frac{1}{2}d = 2 * 4

d = 8

The second term of the sequence is:

f(2) = 3 + 8 = 11

The third term is:

f(3) = 11 + 8 = 20

So, we have:

f(1) = 3

f(2) = 3 + 8

Substitute f(1) for 3

f(2) = f(1) + 8

Express 1 as 2 - 1

f(2) = f(2-1) + 8

Substitute n for 2

f(n) = f(n-1) + 8

Similarly:

f(3) = 11 + 8

Substitute f(2) for 11

f(3) = f(2) + 8

Express 2 as 3 - 1

f(3) = f(3-1) + 8

Substitute n for 3

f(n) = f(n-1) + 8

Hence, the recursive is:

f(n) = f(n-1) + 8 for n  1

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