Sequence Definition and 1000 Threads

  1. L

    Converging Sequence: Basic Steps and Practice Problems

    Homework Statement I was given this homework problem: Show that if ##a_1,a_2, ... ,## is a sequence of real numbers that converges to ##a##, then lim_{n\to \infty}\frac{\sum^n_{k=1} a_k}{n}=a. I was provided a solution but my book never went over such examples or the concrete steps to solve...
  2. D

    Proving divergence of a sequence

    Hello! Please help me to solve following exercise (2.5.8) from Elementary Real Analysis by Thomson-Bruckner: Suppose that a sequence \{s_n\} of positive numbers satisfies the condition s_{n+1} > \alpha s_n for all ##n## where ##\alpha>1.## Show that ##s_n \to \infty.## I can't prove...
  3. E

    Proving that a sequence is within certain bounds

    Homework Statement Define a1=1, and for every n>1, an+1 = an + \frac{1}{an}. Prove that 20 < a200 < 24The Attempt at a Solution I tried a few things to no avail. First, I showed that this is an increasing function by showing an+1 > an. I tried finding a limit, by saying if...
  4. C

    MHB Is a number member of sequence?

    an(n in subindex)=(1/2)*n^2-3n+5/2, when n ≥1 Is number 10 member of that sequence? what about number 6?Create equation to solve it. If someone can help with this problem please, it will be much appreciated!
  5. T

    Solve Sequence Problem: Limit of an as n→∞

    1. the nsider, for n → 1, the sequence an given by an = n log (n/n+1) Determine the limit of the sequence as n→∞, If it exists , or explain why the sequence diverges. In your answers include the names of any rules, theorems or limits you have used. 2. Homework Equations 3. The Attempt at a...
  6. rsyed5

    MHB How to Solve a Geometric Sequence with Given Differences?

    I have no idea how to solve this equation, its in my homework... i know the formula to find the nth term(tn=ar^n-1) but don't know how to solve this: The difference between the first term and second term in a geometric sequence is 6.The difference between the second term and the third term is...
  7. Fernando Revilla

    MHB Find x for Geometric Progression: Solve with Step-by-Step Explanation

    I quote a question from Yahoo! Answers I have given a link to the topic there so the OP can see my response.
  8. B

    A geometric sequence within a arithmetic sequence

    the main question here is that can a sequence * arithmetic * be correct if the difference is also changing in terms of a geometric sequence ?\ now look at this sequence 0.33,0.3333,0.333333 now if we calculate the difference between the first two terms its 0.0033 between the second and...
  9. F

    Hailstone sequence, is it possible to reach 2n starting from n?

    Is it possible, using the Collatz hailstone sequence to ever start at a number n and end up with 2n at some point later in the sequence for values greater than 2? Can you have a sequence that goes n . . . 2n (I don't care what any of the exact values are, I want to know if using variables it is...
  10. anemone

    MHB Sequence of Positive Integers Challenge

    Consider the sequence of positive integers which satisfies a_n=a_{n-1}^2+a_{n-2}^2+a_{n-3}^2 for all $n \ge 3$. Prove that if $a_k=1997$, then $k \le 3$.
  11. J

    Finding a Formula for the General Term of a Sequence

    Homework Statement A bored student enters the number 0.5 in her calculator, then repeatedly computes the square of the number in the display. Taking A0 = 0.5, find a formula for the general term of the sequence {An} of the numbers that appear in the display, and find the limit of the sequence...
  12. J

    Limit of Sequence Homework: Find n22n/(n!)

    Homework Statement Find the limit of n22n/(n!) Homework Equations The Attempt at a Solution First I expand out 2n/(n!) = (2/1)(2/2)(2/3)(2/4)...(2/n) which gets increasingly small as n increases. Now, where does the n2 fit into this? I know the limit to be 0 but I can't get...
  13. Z

    Determine the convergence or divergence of the sequence

    Homework Statement Determine the convergence or divergence of the sequence with the given nth term. If the sequence converges find its limit. an = (1*3*5*...*(2n-1))/(2n)n Homework Equations lim n->infinity an = L The Attempt at a Solution The answer in the book shows: 1/2n *...
  14. anemone

    MHB Find the nth term of the sequence.

    A sequence of positive integers is defined as follows: The first term is 1. Then take the next two even numbers 2, 4. Then take the next three odd numbers 5, 7, 9. Then take the next four even numbers 10, 12, 14, 16 and so on. Find the nth term of the sequence.
  15. A

    Sequence Homework: Finding Terms and Sum for a Specific Sequence

    Homework Statement Let a be a real number such that 1 < a < 2 ,{an} is a sequence defined by a1=a, an+1=|an|-1 (n=1,2,3...) And put sn=a1+a2+a3+...an i)Find the a4,a5,a6,a7 i)Find a4,a5,a6,a7 The Attempt at a Solution I don't even know how to start.Maybe someone could give me an idea.
  16. alyafey22

    MHB Amazing Sequence: 444, 666, 999 - Rofl!

    I should delete one unthanked post to get , 444 666 999 that was just close (Rofl)
  17. anemone

    MHB Sum of a Complex Fraction Sequence

    Find \sum_{x=0}^{101}\frac{\frac{2x}{101}-1}{\frac{3x^2}{10201}-\frac{3x}{101}+1}.
  18. B

    Convergence of this sequence .

    Homework Statement find the limit n\rightarrow∞ of 10n/ n! Homework Equations L hospital rule The Attempt at a Solution took log and separated the num and denom as: n ln10-ln(n!) n ln10-n ln(n)+n 1/n ( ln10 - ln(n)+1) now i...
  19. TheBigBadBen

    MHB Self-Consistency of Sequence of Statements: Which is True?

    Consider the following sequence of statements: $$ S_1: \text{at least 1 of the statements }S_1-S_n \text{ is false}\\ S_2: \text{at least 2 of the statements }S_1-S_n \text{ are false}\\ \vdots \\ S_n: \text{at least } n \text{ of the statements }S_1-S_n \text{ are false} $$ Where $n$ is some...
  20. A

    Is the Intersection of Nested Sets in a Complete Metric Space Nonempty?

    Homework Statement Let (M,d) be a complete metric space and define a sequence of non empty sets F1\supseteqF2\supseteqF3\supseteq such that diam(Fn)->0, where diam(Fn)=sup(d(x,y),x,y\inFn). Show that there \bigcapn=1∞Fn is nonempty (contains one element). Homework Equations The...
  21. M

    Just finished my lower division physics sequence

    Hello everyone, I just wanted to make a post thanking all of those who have helped me over the past couple of years with my physics and math questions, since it would be hard to reach every individual. I am now finally done with the lower division physics sequence and managed to get an A in...
  22. Lebombo

    Is this sequence arithmetic, geometric, or neither?

    Homework Statement Is the sequence \frac{1}{1}, \frac{1}{2}, \frac{1}{3} , \frac{1}{4}...\frac{1}{n} arithmetic or geometric? Homework Equations Common difference and Common ratio formulas The Attempt at a Solution I found the common difference from a_{2} - a_{1} =d_{1} and common...
  23. C

    Sequence of measurable subsets of [0,1] (Lebesgue measure, Measurable)

    Homework Statement Let \left\{E_{k}\right\}_{k\in N} be a sequence of measurable subsets of [0,1] satisfying m\left(E_{k}\right)=1. Then m\left(\bigcap^{\infty}_{k=1}E_{k}\right)=1. Homework Equations m denotes the Lebesgue measure. "Measurable" is short for Lebesgue-measurable. The Attempt...
  24. D

    Prove the sequence ((n)^1/n) / n converges

    Homework Statement prove the sequence ## \frac{n!^{1/n}}{n} ## converges and find its limit Homework Equations n/a The Attempt at a Solution Ok since this question was in a section having to do with the ratio test, I am making an educated guess that we are suppose to show...
  25. Fernando Revilla

    MHB Divergent sequence (Hanym's question at Yahoo Answers)

    Here is the question: Here is a link to the question: Find the limit of sequence? - Yahoo! Answers I have posted a link there to this topic so the OP can find my response.
  26. J

    I proving something about my sequence

    My sequence is a function f:Z+→{H,T} to represent heads and tails. It is defined by f(1),f(2),f(3)f(4),f(5)f(6), ... = H,T,HH,HT,TH,TT,HHH,THH,HTH,..., where you can see that I'm just taking all heads-tails sequences of length 1, then of length 2, etcetera. This ensures (1) that the...
  27. Lebombo

    Understanding Sequence of Partial Sum notation

    {Edit: as of 3:55 eastern time, made corrections to tex and itex mistakes}Is this all kosher in terms of demonstrating accuracy and comprehension of the notation {a_{1} + a_{2}...} = \lim_{n\rightarrow ∞ } \sum_{n=1}^{n} a_{n} So the lower case represents sequences and upper case represents...
  28. R

    Finding the nth Term of a Sequence: 6+13+24+39+...

    How to find nth term of the sequence 6+13+24+39+...
  29. J

    How Do You Program a Sequential LED Light Pattern in MIPS Assembly?

    Hi all, I've only just started MIPS and have been stuck on this introductory lab for a while now. I have 8 LEDs each lit by there corresponding bit being a 1. Hence 0010 0101 at the input would light up LEDS 1, 3 and 6. I need to make LEDs 1-5 light up one at a time and extinguish the...
  30. Albert1

    MHB What is the Value of f(2009) in the Given Recursive Sequence?

    $f(5)=10$ $f(n+3)=\dfrac {f(n)-1}{f(n)+1},\,\, for \,\, all \,\,n\in N$ find f(2009)
  31. S

    Proving a sequence diverges directly

    I want to prove the sequence a(n) = n diverges, directly, without the aid of any theorems. Naturally, I try to prove this by contradiction. Here's my attempt: Let L be a real number such that a(n) converges to L. Then for all e>0, there exists a natural number N s.t. any n>N implies d(a(n) -...
  32. K

    Why L' Hospital's rule cannot apply directly for sequence

    Homework Statement Well, this thread is purposely to clarify my question on the use of L'Hospital's rule for sequence. As I have read from the calculus book, the sequence can be defined such that f:N → ℝ with function f(n)= an where n inside natural numbers,N. So, we cannot apply L'...
  33. P

    Proving a sequence is a cauchy sequence in for the 7 -adic metric

    Homework Statement Show that the sequence (xn)n\inN \inZ given by xn = Ʃ from k=0 to n (7n) for all n \in N is a cauchy sequence for the 7 adic metric. Homework Equations In a metric space (X,dx) a sequence (xn)n\inN in X is a cauchy sequence if for all ε> 0 there exists some M\inN such...
  34. F

    Sequence Convergence & Fixed Point Theorem

    Homework Statement Let g(x)= (2/3)*(x+1/(x^2)) and consider the sequence defined by pn= g(pn-1) where n≥1 a) Determine the values of p0 \in [1,2] for which the sequence {pn} from 0 to infinity converges. b) For the cases where {pn} converges (if any), what is the rate of convergence...
  35. G

    Cauchy sequence and convergeant diameters.

    Suppose (an) is sequence in the metric space X and define Tn={ak:k>n} and diamT=sup{d(a,b):a,b elements of T}. Prove that (an) is Cauchy if and only if diam Tn converges to zero. In what metric spacee does Tn converge? I assumed in (ℝ,de) but this is confusing since the diam of T is...
  36. R

    [Calculus] Sequence Limits: n -> infinity (n/n^n)(Use Sandwich Rule?)

    Homework Statement Use sandwich Rule to find the limit lim n> infinity (a_n) of the sequences, for which the nth term, a_n, is given. Homework Equations ^{lim}_{n\rightarrow∞}\frac{n!}{n^{n}} The Attempt at a Solution I know by just looking at it, n^n Approaches infinity much...
  37. R

    Calculus 2: Sequence Limits Question to the power n?

    Calculus 2: Sequence Limits Question to the power n?? Homework Statement Find the limits (if it exists) to decide which sequences, whose nth term is given below. Homework Equations (\frac{3^{n}-4^{n}}{3n^{2}+4^{n}+7}) The Attempt at a Solution I've done a few of these but as Soon as the...
  38. M

    Definition of liminf of sequence of functions?

    Homework Statement Hi I've come across the term lim inf ##f_n## in my text but am not sure what it means. ##\lim \inf f_n = \sup _n \inf _{k \geq n} f_k## In fact, I am not sure what is supposed to be the output of lim inf f? That is, is it supposed to return a real-valued number, or a...
  39. STEMucator

    Prove every convergent sequence of real numbers is bounded &

    Homework Statement The question : http://gyazo.com/7eb4b86c61150e4af092b9f8afeaf169 Homework Equations Sup/Inf axioms Methods of constructing sequences ##ε-N## ##lim(a_n) ≤ sup_n a_n## from question 5 right before it. I'll split the question into two parts. The Attempt at a...
  40. C

    Prove sequence converges to sup

    Homework Statement Suppose that E is contained in ##\mathbb{R}## is a nonempty bounded set and that ##\sup E## is not in E. Prove that there exists a strictly increasing sequence ##\left\{x_n\right\}## that converges to ##\sup E## such that ##x_n \in E## for all n in ##\mathbb{N}##...
  41. STEMucator

    What is the relationship between the limit and supremum of a sequence?

    Homework Statement http://gyazo.com/d59c730eb9b18dda4504a5fe118c7213 Homework Equations Limit and supremum. The Attempt at a Solution (a) Let : ##b_n = a_n - b## so that ##b_n ≤ 0## Now, ##lim(b_n) = lim(a_n - b) ≤ 0 \Rightarrow a - b ≤ 0 \Rightarrow a ≤ b## Q.E.D (b)...
  42. R

    Problems generalizing a number sequence

    I'm having problems generalizing a number sequence. It involves a couple parameters that I will attempt to explain and show by example. Basically I have a program that takes 3x3 raster segments of a much bigger matrix. The matrix is a logical matrix. What I do is take the a 3x3 raster segment...
  43. P

    Is the Sequence a_n = n / (2^(n+2)) Monotonic and Bounded?

    1. Determine whether the sequence with the given nth term is monotonic & bounded. a_n = (n) / (2^(n+2))2. b_n < b_n+1 3. (n) / (2^(n+2)) < (n+1) / (2^(n+3)) I multiply both side by (2^(n+2)) and (2^(n+3)) (n)(2^(n+3)) < (n+1)(2^(n+2)) Then i distribute and got: (n)(2^(n+3)) < (n)(2^(n+2))...
  44. C

    Proving sequence tends to limit

    Homework Statement Prove that $$\frac{x_n^2 - e}{x_n} \rightarrow 1-e$$ as ##n \rightarrow \infty##, provided ##x_n \rightarrow 1## as n ##\rightarrow \infty##. The Attempt at a Solution The above holds if ##\,\forall\, \epsilon > 0 \,\exists \, N\, \in\, \mathbb{N}## such that if n...
  45. D

    What is the general term of this sequence?

    Could you help me to find the general term of the sequence: ## 1 , \frac{5}{3} , 1 , \frac{15}{17} , 1 , \frac{37}{35} , 1 , \frac{63}{65} ,... ## Thank you!
  46. B

    Sequence of insulating layers of different conductivities for pipe

    Homework Statement Two insulating materials of thermal conductivity K and 2K respectively are to be used as two layers of insulation for lagging a pipe carrying hot fluid. If the radial thickness both the layers is to be same, then - i) the first material (thermal conductivity K) should be...
  47. J

    Can I Make a Sequence for this Data to the nth Term?

    Homework Statement I have a problem where I need to know if I can make a sequence for this data to the nth term. The first term, however, isn't common. Is there any way to somehow make it a sequence? At dose 1 y(1)=De^(0*12*k)/(1-e^(0*12*k)) at dose 2 y(2)=D*e^(1*12*k)/(1-e^(12k)) +...
  48. Logan Land

    MHB Calculating Terms of Sequence: a1,a2,a3,a4

    write the terms a1,a2,a3,a4 of the following sequence. an+1=0.4an+330, a0=550 everytime I get 550 for a1 a2 a3 and a4 is that correct or am I doing it wrong.
  49. Lebombo

    Sequence formula [itex]a_{n}[/itex]=((last term) - (n-1)(common diff))

    Calc 2 will require some basic knowledge of sequences and series. Since this topic has never been covered in any of my past math classes, I am currently learning about sequences and series from scratch. On youtube, I found a video that contains an explanation of the General Term of the...
  50. B

    Geometric sequence question in IB HL mathematics paper 1 november 2010

    Homework Statement The sum S n of the first n terms of a geometric sequence whose nth term is u n is given by 7n-an / 7n Where a > 0 Find an expression for un Find the first term and the common ratio of the sequence Consider the sum to infinity of the sequence Determine...
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