Composite Definition and 401 Threads

  1. anemone

    MHB Prove a sum is a composite number

    For positive integers $p,\,q,\,r,\,s$ such that $ps=q^2+qr+r^2$, prove that $p^2+q^2+r^2+s^2$ is a composite number.
  2. A

    MHB Composite Functions and Exponential Growth

    Hey guys, Few more questions for the problem set I've been working on. I'm doubting some of my answers and I'd appreciate some help. Question: The first one starts off easy but I found that it gets progress more challenging later on. So the rate of spread should be p'(t) which is: p'(t) =...
  3. A

    MHB Composite functions and substitutions Quick Question

    Hey guys, I have a couple more questions about this problem set I've been working on. I'm doubting some of my answers and I'd appreciate some help. Question: For the first one, since f o g = √(√x+5)-2), the domain is [-1,infinity) Likewise, g o f = √(√x-2)+5) and the domain is [27,infinity)...
  4. ShayanJ

    How composite particles have definite spin?

    Consider a composite particle. Its spin is determined by the spins of its constituent particles. But the constituent particles are in a superposition of different spin states and so don't have a definite spin. So it seems it shouldn't be possible to ascribe a definite spin to the composite...
  5. J

    Composite moment of inertia question:

    Good morning PF, I am having some difficulty finding info on calculating a composite moment of inertia. The section I am working with is 8 separate columns (WT5x15) arranged evenly spaced around the circumference of a circle. You can see what I'm taking about in the attached jpg. I found...
  6. Tesladude

    How to transmit composite video

    Can I use a 315MHz transmitter module to send a composite video signal to another reciever module?
  7. O

    Expectation value of composite observable in singlet state

    Homework Statement I've been reading Leonard Susskind's Theoretical Minimum volume on QM, and enjoying it quite a bit - the book doesn't include exercise solutions at the end though, and if they exist online for this volume I haven't been able to find them. (Perhaps if such solutions...
  8. evinda

    MHB There are infinitely many composite numbers

    Hey again! (Rock)(Wasntme) I want to show that there are infinitely many composite numbers $n$,for which stands: $$a^{n-1} \equiv 1 \pmod n$$ So,it must be: $n \mid a^{n-1}-1$ But how can I show that there are infinitely many such $n$ ?? (Thinking)
  9. evinda

    MHB Proving the Compositeness of n^4+1: A Scientific Approach

    Hello! (Smile) I am looking at the following exercise: If $n>1$,show that $n^4+1$ is composite. According to my notes,it is like that: $$n^4+4=(n^2)^2+2^2+2 \cdot 2 \cdot n^2-2 \cdot 2 \cdot n^2=(n^2+2)^2-4n^2=(n^2+2-2n)(n^2+2+2n)$$ To check if it is composite,we have to check if...
  10. anemone

    MHB Is 27x^6+27x^3y^3+8y^6 Composite for Positive Integers x and y?

    Prove that the number $27x^6+27x^3y^3+8y^6$ is composite for any positive integers $x$ and $y$.
  11. J

    Functional and composite function

    What is the difference between a functional and a composite function? Also, look those implicit equations: ##F(x, y(x))=0##, ##F(t, \vec{r}(t))=0##, ##F(x, y(x), y'(x), y''(x))=0##, ##F(t, \vec{r}(t), \vec{r}'(t))=0##... Can be understood that ##F## is the functional?
  12. H

    MATLAB Composite Simpsons 1/3 matlab code

    hey guys, So I'm working on a MATLAB function that uses simpsons 1/3 rule to find an integral. This is what I have done so far, but I'm not 100% confident.. I seem to get double when I use greater segments. If anyone would be able to have a look at give me some tips that would be very much...
  13. G

    2D heat conduction of layered composite model

    Hi, I am trying to formulate a 2D model to calculate the temperature change over time in a composite material. The material consists of several layers, and is heated from all edges by a known temperature vs time profile. I was thinking of creating a finite element model. Can someone...
  14. E

    Composite materials for payload shroud

    We are looking at designing a 10" diameter, 48" long payload shroud (Ogive nose cone) for a large hobby rocket. We have done an aeroheating analysis based on the trajectory, so we have the max temp. experienced during ascent at several body points. We want to make the shroud out of composites...
  15. R

    Composite beam flexural modulus

    If I have a composite beam or an T beam where the top of the T is of significantly higher stiffness than the vertical part. is it true that the further a stiffness material is from the neutral axis the greater the effect on the overall stiffness is? is it possible to calculate a new flexural...
  16. L

    Composite function of a piecewise function

    Homework Statement Given that I have a doubling function : f(x)=2x (for 0≤x<0.5) and 2x-1 (for 0.5≤ x<1) Homework Equations What is f(f(x))? The Attempt at a Solution f(f(x))=4x for the first one and 4x-3 for the second part but not sure what to do about the domain...
  17. C

    What Determines the Domain of f(g(x)) for Given Functions?

    Let's say f(x) = sqrt(x-1) And g(x) =x^2 What is the domain of f(g(x)) Well the domain of g(x) is all real numbers and the equation for the new function is sqrt(x^2-1) Am I right to say that the domain for f(g(x)) is x greater than or equal to 1 and less than and equal to -1??
  18. A

    Stationary waves in composite strings

    Dear All, I was reading the concept of stationary waves in composite string ABC made up of joining two strings AB AND BC with different mass per unit length and a joint at 'B'.the two ends of the composite string are clamped at 'A' and 'C' and a transverse wave is set up by an external source...
  19. S

    Simplifying an Infinite Composite Recursion in a System of Equations

    Hello, I'm working with a system of equations that has an infinite recursion function, and am wondering if its possible to simplify or remove the recursion in terms of the other functions in the system. Any insight into the framework or family of this system is appreciated. Given two...
  20. C

    Inputs and outputs of composite function

    Homework Statement Can someone describe the input and output method to find the domain and ranges of composite functions to me?? Homework Equations The Attempt at a Solution Example: f(g(x)) first you find the domain of g(x) Then you find the range of g(x) y= G(x) that will...
  21. T

    Integration of a composite function

    y=f(x),K=F(y), and dF(y)/dy=y^2/y', (1) then dF(x)=y^2*dx; so, F(x)=int(y^2*dx)=int((f(x)^2)*dx); then we obtain, F(x)=(f(x))^3/(3*f'(x))+C; substitution of y=f(x) into F(x), we get, F(y)=y^3/(3*y')+C; (2) using the result...
  22. T

    Derivative of a composite function

    y =f(x), and y'=df(x)/dx, F(y)=y^3+(y')^2 how to deal with the (y')^2 when i calculate dF(y)/dy? thanks.
  23. B

    Centroid of composite area (one question)

    I was doing this example from my textbook and looked at the solution guide. I'm confused as to where the textbook got a certain number. In the numerator of their work, they got (1)(6)(2), which I'm assuming is the width of the skinny rectangle, the total length of the bottom section...
  24. P

    High strength ceramic vs metals vs metal fiber composite

    metals are generally considered more useful for high strength parts because ceramics break when exposed to sudden shock, but what about when a continuous force is applied to a ceramic and a metal of the same dimensions by a high strength ceramic i mean a higher hardness than the metal (such as...
  25. G

    Stokes theorem, parametrizing composite curves

    Homework Statement Calculate the line integral: F = <xz, (xy2 + 2z), (xy + z)> along the curve given by: 1) x = 0, y2 + z2 = 1, z > 0, y: -1 → 1 2) z = 0, x + y = 1, y: 1→0 3) z = 0, x-y = 1, y: 0 → -1 Homework Equations The Attempt at a Solution I don't think the...
  26. J

    Looking for composite picture of Milky-way from outside galaxy

    Hi, I recall some years ago seeing a composite picture of what our galaxy would look like from outside the galaxy, for example from Andromeda but was not able to find one or even how to search for it on the web. I was wondering if anyone here is familiar with it and perhaps even if we've...
  27. M

    Can Gravity Be Explained as a Composite of Electromagnetic and Strong Forces?

    I've been looking for work on this, and I was hoping someone could confirm or deny that anyone has done any before. I am referring to gravity being a composite of the electromagnetic (or maybe electro-magnetic-strong-weak) force between many different pieces of matter with a mostly nullified net...
  28. B

    Gravitional Force On Composite Body

    Why is finding the gravitational force on the center of mass of a composite body the same as finding the gravitational force on each individual constituent of the composite body?
  29. G

    Calculating Correlation of Composite Operators

    I have probably a silly question about correlation functions of composite operators. Why can't you just calculate a correlator with fields at different points x1, x2, x3, ... and then set a couple of the points equal at the end of the calculation to get the result? e.g., \langle 0...
  30. M

    MHB Why Does Subtraction Become Addition in Composite Functions?

    g(x)=−4x2−5x f(x)=−3x2+7x−5(g(x)) f(g(−1))=? First, let's solve for the value of the inner function, g(−1). Then we'll know what to plug into the outer function. g(−1)=−4(−1)2+(−5)(−1)I don't understand why they transformed the minus symbol into an addition symbol. This has happened a few...
  31. S

    Is a tennis ball technically a composite or a polymer?

    Homework Statement Under which class of materials would the following materials be categorized? What are/is the primary bond type(s) in each material/object? a. Tennis Ball Homework Equations The Attempt at a Solution We'll consider a very simple and standard tennis ball...
  32. Petrus

    MHB Integrate Sine and Square root Composite Function

    Hello MHB, I got stuck on integrate this function \int \frac{\sin^3(\sqrt{x})}{\sqrt{x}}dx my first thinking was rewrite it as \int \frac{\sin^2(\sqrt{x})\sin(\sqrt{x})}{\sqrt{x}}dx then use the identity \cos^2(x)+\sin^2(x)=1 \ \therefore \sin^2x=1- \cos^2(x) \int...
  33. S

    Comp Sci How to tell Fortran to get rid of composite numbers?

    Problem Statement: Do the sieve of Eratosthenes from 2 to 100 and find all the primesSo I'm trying to do the sieve of Eratosthenes in fortran 90 (I'm using Plato IDE)My efforts to solve this/ method to use: Obviously, I want the program to do a LOOP starting with every whole number from 2...
  34. M

    What is the best method for determining fiber load in a composite material?

    Hello there, I am wondering if some specilalist would point in me in the direction of procedures to determine the load in a fiber in a composite material made of aligned fibers (let's say at alternating angles $$+/- \alpha$$). I understand you could simply compute the strain in a convenient...
  35. A

    Mass Moment of Inertia of a Composite Body

    Homework Statement In the image attached, I'm asked to find the mass moment of inertia about an axis at point O that's perpendicular to the page. The Attempt at a Solution The only question about this problem that I have is: Can I divide the composite body at point O and find the...
  36. B

    I want to prove if the composite are equal to each other

    Given f:{0,1}n→{0,1}n, define f′:{0,1}2n→{0,1}2n as follows: for x,r∈{0,1}n define f′(x∘r):=f(x)∘r (where ∘ denotes concatenation). Prove that if f(⋅) is one way permutation then so is f′(⋅). i don't understand f′(x∘r):=f(x)∘r how to decompose it in order to prove it I tried proving it by...
  37. Saitama

    Solving Composite Functions: Find g(3) with g(2)=37

    Homework Statement Suppose f(x) and g(x) are non-zero polynomials with real coefficients, such that f(g(x))=f(x)⋅g(x). If g(2)=37, what is g(3)? Homework Equations The Attempt at a Solution I have no idea where to begin this with. At x=2, f(g(2))=f(2).g(2) f(37)=37f(2) What...
  38. B

    Infinitely many composite numbers

    Homework Statement Prove that there are infinitely many n such that 6n+1 and 6n-1 are both composite. Homework Equations The Attempt at a Solution I have no idea where to start. I was thinking that this must be some form of Euclid's theorem but I don't know how to work that into...
  39. A

    Understanding Spin in Composite Systems

    Suppose you have an electron and a proton, which both can have either spin up or down. The possible combinations are: \uparrow\downarrow, \downarrow\uparrow, \uparrow\uparrow, \downarrow\downarrow But for some reason my book only allows a linear combination of the two first since they both...
  40. E

    Partition Function of a Composite System (Product Rule and Temperature)

    Homework Statement Show that the partition function for a composite system, let's call it '3', composed of systems '1' and '2' is the product of the partition functions of '1' and '2' independently.Homework Equations Kittel defines partition functions using the fundamental temperature τ (which...
  41. B

    One to one and onto in composite function

    Homework Statement I just want to make sure that I am correct. if we have a composite function f(g(x)). Homework Equations f(g(x)) is onto if and only if both f(x) and g(x) are onto f(g(x)) is one to one if and only if or both f(x) and g(x) are one to one The Attempt at a Solution...
  42. P

    Composite system, rigged Hilbert space, bounded unbounded operator, CSCO, domain

    Is something wrong in my assertions below? Suppose we have two quantum systems N and X. Let N is described by discrete observable \hat{n} (bounded s.a. operator with discrete infinite spectrum) with eigenvectors |n\rangle. Let X is described by continuous observable \hat{x} (unbounded s.a...
  43. Y

    MHB Odd Composite Property 1: A Unique Factorization Rule

    Hi, For any odd composite 'N', let u = (N-1)/2, v = u+1, then u^2(mod p) = v^2(mod p) if and only if 'p' is a factor of 'N'.
  44. Y

    Is there a relationship between odd composite numbers and their factors?

    Hi, For any odd composite 'N', let u = (N-1)/2, v = u+1, then u^2(mod p) = v^2(mod p) if and only if 'p' is a factor of 'N'. For more info please visit kadinumberprops.blogspot.in
  45. U

    Create Composite Ranking of Items Ranked in Multiple Categories

    Hey all, So the idea is that I'm trying to create a composite ranking system of items that are already in different categories. For example, suppose there are 4 houses that a buyer is choosing from. These 4 houses are ranked 1-4 in each of the categories such as affordability, location, and...
  46. A

    Center of mass of composite body

    Homework Statement In the image below, calculate the center of mass (x-bar,y-bar) of the composite body. Homework Equations I've used all of the equations for area for the shapes needed (triangle, square, circle). The Attempt at a Solution I have attached my calculations and...
  47. I

    Invert a triple composite function p(q(r(x)))

    Hey, Let ##(f,g) \in B^A## where ##A## and ##B## are non-empty sets, ##B^A## denotes the set of bijective functions between ##A## and ##B##. We assume that there exists ##h_0: A \rightarrow A## and ##h_1: B \rightarrow B## such that ##f = h_1 \circ g \circ h_0 ##. This implies that ##g =...
  48. B

    Integration of composite derivative of function

    Homework Statement While I was in school I thought to see what a function whose derivative is always perpendicular to another functions derivative would look like, so for example for X^2 we have -ln(x)/2. Homework Equations Well all those integration tables I guess The Attempt at a...
  49. S

    Composite of piecewise functions

    Homework Statement Find f°g for each pair of functions f and g.Homework Equations f(x) = {x+1, if x≤0 or 2x, if x>0 g(x) = {2x, if x≤-1 or -x, if x>-1 The Attempt at a Solution I am able to determine the following: (f°g)(x) = {2x+1, -2x, -x+1 However, these functions carry intervals, and...
  50. O

    Calculating optimum thickness of the insulation for composite wall

    Homework Statement A wall is required to be insulated by embedding wood within concrete. the total thickness of the concrete and wood are 10cm and 1 cm respectively and are fixed due to structural constraints. determine the minimum heat leak into the room if the location of the wood can be...
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