1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Ainat [17]
3 years ago
15

2,17,82,257,626,1297 next one please ?​

Mathematics
1 answer:
In-s [12.5K]3 years ago
4 0

The easy thing to do is notice that 1^4 = 1, 2^4 = 16, 3^4 = 81, and so on, so the sequence follows the rule n^4+1. The next number would then be fourth power of 7 plus 1, or 2402.

And the harder way: Denote the <em>n</em>-th term in this sequence by a_n, and denote the given sequence by \{a_n\}_{n\ge1}.

Let b_n denote the <em>n</em>-th term in the sequence of forward differences of \{a_n\}, defined by

b_n=a_{n+1}-a_n

for <em>n</em> ≥ 1. That is, \{b_n\} is the sequence with

b_1=a_2-a_1=17-2=15

b_2=a_3-a_2=82-17=65

b_3=a_4-a_3=175

b_4=a_5-a_4=369

b_5=a_6-a_5=671

and so on.

Next, let c_n denote the <em>n</em>-th term of the differences of \{b_n\}, i.e. for <em>n</em> ≥ 1,

c_n=b_{n+1}-b_n

so that

c_1=b_2-b_1=65-15=50

c_2=110

c_3=194

c_4=302

etc.

Again: let d_n denote the <em>n</em>-th difference of \{c_n\}:

d_n=c_{n+1}-c_n

d_1=c_2-c_1=60

d_2=84

d_3=108

etc.

One more time: let e_n denote the <em>n</em>-th difference of \{d_n\}:

e_n=d_{n+1}-d_n

e_1=d_2-d_1=24

e_2=24

etc.

The fact that these last differences are constant is a good sign that e_n=24 for all <em>n</em> ≥ 1. Assuming this, we would see that \{d_n\} is an arithmetic sequence given recursively by

\begin{cases}d_1=60\\d_{n+1}=d_n+24&\text{for }n>1\end{cases}

and we can easily find the explicit rule:

d_2=d_1+24

d_3=d_2+24=d_1+24\cdot2

d_4=d_3+24=d_1+24\cdot3

and so on, up to

d_n=d_1+24(n-1)

d_n=24n+36

Use the same strategy to find a closed form for \{c_n\}, then for \{b_n\}, and finally \{a_n\}.

\begin{cases}c_1=50\\c_{n+1}=c_n+24n+36&\text{for }n>1\end{cases}

c_2=c_1+24\cdot1+36

c_3=c_2+24\cdot2+36=c_1+24(1+2)+36\cdot2

c_4=c_3+24\cdot3+36=c_1+24(1+2+3)+36\cdot3

and so on, up to

c_n=c_1+24(1+2+3+\cdots+(n-1))+36(n-1)

Recall the formula for the sum of consecutive integers:

1+2+3+\cdots+n=\displaystyle\sum_{k=1}^nk=\frac{n(n+1)}2

\implies c_n=c_1+\dfrac{24(n-1)n}2+36(n-1)

\implies c_n=12n^2+24n+14

\begin{cases}b_1=15\\b_{n+1}=b_n+12n^2+24n+14&\text{for }n>1\end{cases}

b_2=b_1+12\cdot1^2+24\cdot1+14

b_3=b_2+12\cdot2^2+24\cdot2+14=b_1+12(1^2+2^2)+24(1+2)+14\cdot2

b_4=b_3+12\cdot3^2+24\cdot3+14=b_1+12(1^2+2^2+3^2)+24(1+2+3)+14\cdot3

and so on, up to

b_n=b_1+12(1^2+2^2+3^2+\cdots+(n-1)^2)+24(1+2+3+\cdots+(n-1))+14(n-1)

Recall the formula for the sum of squares of consecutive integers:

1^2+2^2+3^2+\cdots+n^2=\displaystyle\sum_{k=1}^nk^2=\frac{n(n+1)(2n+1)}6

\implies b_n=15+\dfrac{12(n-1)n(2(n-1)+1)}6+\dfrac{24(n-1)n}2+14(n-1)

\implies b_n=4n^3+6n^2+4n+1

\begin{cases}a_1=2\\a_{n+1}=a_n+4n^3+6n^2+4n+1&\text{for }n>1\end{cases}

a_2=a_1+4\cdot1^3+6\cdot1^2+4\cdot1+1

a_3=a_2+4(1^3+2^3)+6(1^2+2^2)+4(1+2)+1\cdot2

a_4=a_3+4(1^3+2^3+3^3)+6(1^2+2^2+3^2)+4(1+2+3)+1\cdot3

\implies a_n=a_1+4\displaystyle\sum_{k=1}^3k^3+6\sum_{k=1}^3k^2+4\sum_{k=1}^3k+\sum_{k=1}^{n-1}1

\displaystyle\sum_{k=1}^nk^3=\frac{n^2(n+1)^2}4

\implies a_n=2+\dfrac{4(n-1)^2n^2}4+\dfrac{6(n-1)n(2n)}6+\dfrac{4(n-1)n}2+(n-1)

\implies a_n=n^4+1

You might be interested in
Amazon Inc. has been sued for following three alleged infringements of law: (1) Unauthorized use of a trademark; the claim is fo
Dimas [21]

The International Financial Reporting Standards developed standards can

be implemented to ascertain the provisions and disclosures to be made.

The correct responses are;

According to the financial reporting standard, the contingent liability that

Amazon Inc. should disclose and the provision that Amazon Inc. should

recognize, based on the legal consent are;

Lawsuit 1: It is not required to make provision or disclosure because the

probability of the lawsuit progressing is remote and therefore, the

Company will not be required to payout money or lose economic benefits.

Lawsuit 2: The likelihood of the Company having pay the displaced

employees is high however, the amount payable is $2 million, and

therefore, a provision of $2 million is required in the financial reporting.

Lawsuit 3: The Company is not legally obliged to pay for or perform the

cleanup, but based on the relationship between the Company's waste

location, the river, and the community, there is a constructive obligation,

the amount of which cannot be determined with reliability.

Therefore, there is a requirement for disclosure as a contingent liability,

and not a provision as the claim cannot be classified as a provision.

Learn more here:

brainly.com/question/17371330

8 0
2 years ago
elliot counts a group of coims starting with rhe quarters his sister counts tje same coins.she starts counting the pennies.will
Leona [35]
Yes because they are counting the same group
5 0
3 years ago
Read 2 more answers
Find the midpoint of the line segment whose endpoints are (0,1/2 ) and (0,3/4 ).
Ksivusya [100]
Formula of the midpoint:
x =(x₁+x₂)/2    and y = (y₁+y₂)/2

Plugin the respective value
for A(0,1/2)  and B(0, 3/4)

x= (0+0)/2 = 0
y = (1/2 + 3/4)/2 = 5/8 

Then the midpoint of the line segment whose endpoints are (0,1/2 ) and (0,3/4 ). is M(0, 5/8) or M(0, 0.625)

8 0
3 years ago
Read 2 more answers
Put the following equation of a line into slope-intercept form, simplifying all
Brilliant_brown [7]

Answer:

y = -x - 4

General Formulas and Concepts:

<u>Pre-Algebra</u>

  • Equality Properties

<u>Algebra I</u>

Slope-Intercept Form: y = mx + b

  • m - slope
  • b - y-intercept

Step-by-step explanation:

<u>Step 1: Define</u>

x + y = -4

<u>Step 2: Rewrite</u>

<em>Find slope-intercept form</em>

  1. Subtract <em>x</em> on both sides:                    y = -x - 4
8 0
2 years ago
If you shift the quadratic parent function, Flx) =x, down 9 units, what is the equation of the new function?​
Mashutka [201]

Answer:

y = x-9

Step-by-step explanation:

6 0
3 years ago
Other questions:
  • a rare coin was bought for $30.00 2 years ago.It is now worth $75.00 . What is the percent increase in worth?​
    10·1 answer
  • Write a numerical expression that equals 24.Include an exponent.
    15·2 answers
  • How can i find the slope of a line
    12·2 answers
  • PLs help asap :( i have no idea how to do sigma notation
    13·1 answer
  • HELP ASAP PLEASE HELPPPPPPP PLEASE
    8·1 answer
  • I bought 2 1/2 gallons of paint but i only used 1/2 gallon of the paint. how much paint do i have left?
    5·1 answer
  • I don't understand help​
    6·2 answers
  • Pls just answer it with A B C D makes life simpler
    5·1 answer
  • Write an integer for this situation: a profit of $12
    8·1 answer
  • For what value of x is the
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!