Let $x\in\mathbb R$ and $$\tilde x_n:=\frac1{2^n}\lfloor2^nx\rfloor\;\;\;\text{for }n\in\mathbb N\;.$$ It's easy to show that $\tilde x_n\uparrow x$ for $n\to\infty$. Now, let $$x_n:=\frac1{2^n}\lceil2^nx\rceil\;\;\;\text{for }n\in\mathbb N\;.$$ Can we analogously show that $x_n\downarrow x$ for $n\to\infty$? I've tried to use $$x-1<\lfloor x\rfloor\le x\le\lceil x\rceil<x+1\tag 1$$ together with the assumption $$2^nx=k+\delta\tag 2$$ for some $k\in\mathbb Z$ and $\delta\in[0,1)$. With this approach I was able to show $\tilde x_n\le\tilde x_{n+1}$, but I wasn't able to show $x_n\ge x_{n+1}$.
2026-03-27 15:19:04.1774624744
Can we show that $\frac1{2^n}\lceil2^nx\rceil\downarrow x$ for $n\to\infty$?
35 Views Asked by Bumbble Comm https://math.techqa.club/user/bumbble-comm/detail At
1
There are 1 best solutions below
Related Questions in SEQUENCES-AND-SERIES
- How to show that $k < m_1+2$?
- Justify an approximation of $\sum_{n=1}^\infty G_n/\binom{\frac{n}{2}+\frac{1}{2}}{\frac{n}{2}}$, where $G_n$ denotes the Gregory coefficients
- Negative Countdown
- Calculating the radius of convergence for $\sum _{n=1}^{\infty}\frac{\left(\sqrt{ n^2+n}-\sqrt{n^2+1}\right)^n}{n^2}z^n$
- Show that the sequence is bounded below 3
- A particular exercise on convergence of recursive sequence
- Proving whether function-series $f_n(x) = \frac{(-1)^nx}n$
- Powers of a simple matrix and Catalan numbers
- Convergence of a rational sequence to a irrational limit
- studying the convergence of a series:
Related Questions in CONVERGENCE-DIVERGENCE
- Finding radius of convergence $\sum _{n=0}^{}(2+(-1)^n)^nz^n$
- Conditions for the convergence of :$\cos\left( \sum_{n\geq0}{a_n}x^n\right)$
- Proving whether function-series $f_n(x) = \frac{(-1)^nx}n$
- Pointwise and uniform convergence of function series $f_n = x^n$
- studying the convergence of a series:
- Convergence in measure preserves measurability
- If $a_{1}>2$and $a_{n+1}=a_{n}^{2}-2$ then Find $\sum_{n=1}^{\infty}$ $\frac{1}{a_{1}a_{2}......a_{n}}$
- Convergence radius of power series can be derived from root and ratio test.
- Does this sequence converge? And if so to what?
- Seeking an example of Schwartz function $f$ such that $ \int_{\bf R}\left|\frac{f(x-y)}{y}\right|\ dy=\infty$
Related Questions in CEILING-AND-FLOOR-FUNCTIONS
- System of simultaneous equations involving integral part (floor)
- Is there a limit?
- Largest value of sequence
- Does $x+\sqrt{x}$ ever round to a perfect square, given $x\in \mathbb{N}$?
- Fractional part of integer multiples
- Proof regarding the ceiling function.
- Find number of solutions of $(x-1)^2+\lceil x \rceil=4$
- Let $n$ is a natural number. Find $\int_0^n 2x \lfloor x \rfloor dx$
- Inverse cosine inside floor function derivative
- Floor function problem
Related Questions in MONOTONE-FUNCTIONS
- Monotonicity of a differentiable positive function
- Convexity, Monotonicity, Positivity
- Monotonicity of function $f(x)=\sqrt[3]{(x+1)^2}-\sqrt[3]{x^2}$
- Sufficient/necessary condition for submatrix determinant (minor) that decreases with size?
- Composition of a non-increasing and a non-decreasing function
- Choosing right options based on given condition of differentiabile function
- Nowhere Monotonic/ Differentiable function proof
- Lebesgue's monotone convergence theorem, - boundedness
- Power of a decreasing sequence of positive reals.
- Does a monotone function exist such that there is a "simple" closed form for itself as well as its inverse?
Trending Questions
- Induction on the number of equations
- How to convince a math teacher of this simple and obvious fact?
- Find $E[XY|Y+Z=1 ]$
- Refuting the Anti-Cantor Cranks
- What are imaginary numbers?
- Determine the adjoint of $\tilde Q(x)$ for $\tilde Q(x)u:=(Qu)(x)$ where $Q:U→L^2(Ω,ℝ^d$ is a Hilbert-Schmidt operator and $U$ is a Hilbert space
- Why does this innovative method of subtraction from a third grader always work?
- How do we know that the number $1$ is not equal to the number $-1$?
- What are the Implications of having VΩ as a model for a theory?
- Defining a Galois Field based on primitive element versus polynomial?
- Can't find the relationship between two columns of numbers. Please Help
- Is computer science a branch of mathematics?
- Is there a bijection of $\mathbb{R}^n$ with itself such that the forward map is connected but the inverse is not?
- Identification of a quadrilateral as a trapezoid, rectangle, or square
- Generator of inertia group in function field extension
Popular # Hahtags
second-order-logic
numerical-methods
puzzle
logic
probability
number-theory
winding-number
real-analysis
integration
calculus
complex-analysis
sequences-and-series
proof-writing
set-theory
functions
homotopy-theory
elementary-number-theory
ordinary-differential-equations
circles
derivatives
game-theory
definite-integrals
elementary-set-theory
limits
multivariable-calculus
geometry
algebraic-number-theory
proof-verification
partial-derivative
algebra-precalculus
Popular Questions
- What is the integral of 1/x?
- How many squares actually ARE in this picture? Is this a trick question with no right answer?
- Is a matrix multiplied with its transpose something special?
- What is the difference between independent and mutually exclusive events?
- Visually stunning math concepts which are easy to explain
- taylor series of $\ln(1+x)$?
- How to tell if a set of vectors spans a space?
- Calculus question taking derivative to find horizontal tangent line
- How to determine if a function is one-to-one?
- Determine if vectors are linearly independent
- What does it mean to have a determinant equal to zero?
- Is this Batman equation for real?
- How to find perpendicular vector to another vector?
- How to find mean and median from histogram
- How many sides does a circle have?
Well,
$$x_n - x_{n+1} = \frac{2\lceil 2^n x\rceil - \lceil 2^{n+1}x\rceil}{2^{n+1}} \geqslant 0$$
since $2\lceil y\rceil \geqslant \lceil 2y\rceil$ for all $y\in \mathbb{R}$.