In mathematics, a coefficient is a multiplicative factor in some term of a polynomial, a series, or any expression; it is usually a number, but may be any expression (including variables such as a, b and c). When variables appear in the coefficients, they are often called parameters, and must be clearly distinguished from those representing other variables in an expression.
For example,
2
x
2
−
x
+
3
{\displaystyle 2x^{2}-x+3}
, has the real coefficients 2, -1, and 3 respectively, and
a
x
2
+
b
x
+
c
{\displaystyle ax^{2}+bx+c}
, has coefficient parameters a, b, and c respectively assuming x is the variable of the equation.
The constant coefficient is the coefficient not attached to variables in an expression. For example, the constant coefficients of the expressions above are the real coefficient 3 and the parameter represented by c.
Similarly, the coefficient attached to the highest multiplicity of the variable in a polynomial is referred to as the leading coefficient. For example in the expressions above, the leading coefficients are 2 and the parameter represented by a.
The binomial coefficients occur in the expanded form of
(
x
+
y
)
n
{\displaystyle (x+y)^{n}}
, and are tabulated in Pascal's triangle.
Homework Statement
y'' + 9y = 3sin(3x) + 3 + e^{3x}
Homework EquationsThe Attempt at a Solution
This is my first post here so let me know if I've done anything wrong, I've been looking at questions here for a long time though ^^.
So the problem asks me to solve for one particular solution...
For a simple equilibrium or non-equilibrium chemical reaction, while I understand that the ratio of the coefficients of each reactant/product is mathematically equal to the molar ratio, I am not quite sure whether or not it is equal to the ratio of concentrations of each component in the...
Hello,
I am in an introductory undergraduate course on ODEs, currently on the method of variation of constants to solve nonhomogenous equations.
I am noticing that with many of these problems, when solving for constants after plugging in my guessed values for y I end up with enormous...
When talking about ordinary (real) linear differential equations with constant coefficients the idea is that we are dealing with the vector space of real functions over the field of real numbers. But when we allow the coefficients of a linear differential equation to be functions are we dealing...
Homework Statement
An object consists of 3 connected masses as seen in the figure. None of the surfaces have friction except the surface on m1 which has the coefficients μs=0.4 y μk=0.3.
What is the acceleration of each one of the masses?
It looks like the following image but m1 is the table...
My task is to find Linear homogeneous D.E. with constant coefficients which has solutions:
$$\\\varphi 1(x)=x^2,\varphi 2(x)=e^{-3x},\varphi 3(x)=cos(5x)$$ Any idea?
Hi,
I have an ordinary least squares setup y = Ac where A is an NxM (N>>M) matrix, c the unknown coefficients and y the measurements.
Now WEIGHTED least squares allows to weight the MEASUREMENTS if, for example, some measurements are more important or contain a lower variance.
However...
I have around 550 asymmetrical sigmoid curves fitted to a function with 4 varying coefficients. Each of these curves represent strength as a function of time and temperature for a different compound. Each compound is made up of varying substances at varying concentrations.
Overall, I have 550...
I've found a number of papers about how to calculate Talmi-Moshinsky coefficients. For example W. Tobocman Nucl. Phys A357 (1981) 293-318 and FORTRAN code base on it Y.-P. Gan et al. Comput. Phys. Commun. 34 (1985) 387.
This works well if I want to calculate matrix elements that only depend on...
I'm doing a practice problem I found online, and I get a solution, but I think it should have a sine term in it. I looked up the solution, and most sites say to use variation of parameters, but is it possible to use the method of undetermined coefficients?
The problem is as follows: y'' + 4y...
Hello,
Does anyone know the value of the coefficients of friction between the following surfaces? (I've searched all over internet and literature but cannot find them :( )
1) Aluminium on concrete.
2) Steel on concrete.
3) Iron on concrete.
Thanks a lot!
Dear Fellows,
If we fit our data to a quadratic equation then What is meant by standard error for linear and quaratic coefficients ? I know that standard error is the standard deviation from the Sampling data. But for individual coefficients what is its interpretation ?
Best Wishes
Masood
What the title states. Is it possible? I can't seem to find a way (at least, from the massive stash of PDF files I downloaded about VLE/EOS) on how to employ NRTL activity coefficients with the Soave-Redlich-Kwong EOS.
In other words, is there a way to get the activity coefficient models like...
Hi, I came across this statement while I was reading an article on resolution of vector in arbitrary basis.
"v = αa + βb + γc ---(1) , where a, b and c are three independent vectors.
we observe that the coefficient α cannot involve any overlap of v with either b or c ; β cannot
involve any...
I have a numerical simulation where I'm randomly varying an input parameter.
This results in variations in three output parameters: A, B and C. The output parameters can be assumed to have normal distributions, but are correlated to each other.
If I calculate the mean and standard...
Hey! :o
I have to solve the following initial and boundary value problem:
$$u_t=u_{xx}, 0<x<L, t>0 (1)$$
$$u(0,t)=u_x(L,t)=0, t>0$$
$$u(x,0)=x, 0<x<L$$
I did the following:
Using the method separation of variables, the solution is of the form: $u(x,t)=X(x)T(t)$
Replacing this at $(1)$, we...
Hey! :o
Having the problem:
$$v_t=v_{xx}, 0<x<1, t>0$$
$$v(0,t)=v_x(1,t)=0, t>0$$
$$v(x,0)=e^x-x$$
I have found that the solution of the problem is of the form
$$v(x,t)=\sum_{n=0}^{\infty}{A_n \sin{(\frac{(2n+1) \pi x}{2})} e^{-(\frac{(2n +1) \pi}{2})^2t}}$$
Using the boundary condition...
I'm looking at how a l j1,j2,jm> state can be operated on by the ladder operators, changing the value of m, and how this state can be expressed as a linear combination of l j1, j2, m1, m2> states.
Where the following relationships must be obeyed (x2):
m=m1+m2
l j1-j2 l ≤ j ≤ j1+j2
So...
The question asks to use Fresnel's equations at normal incidence to find the ratio of the refractive indexes of the two materials. We are told equal energy is transmitted and reflected and that both media are non-magnetic and non-conducting dielectrics.
So I know that the ratio of Er/Ei and...
Hey! :o
I have to solve the following boundary value problem:
$$u_{xx}+=u_{yy}=0, 0<x<a, 0<y<b$$
$$u_x(0,y)=u_x(a,y)=0, 0<y<b$$
$$u(x,0)=x, u_y(x,b)=0, 0<x<a$$
By using the method of separation of variables, the solution is of the form $u(x,y)=X(x)Y(y)$.
By substituting this it the problem we...
Problem:
Evaluate
$$\mathop{\sum \sum}_{0\leq i<j\leq n} (-1)^{i-j+1}{n\choose i}{n\choose j}$$
Attempt:
I wrote the sum as:
$$\sum_{j=1}^{n} \sum_{i=0}^{j-1} (-1)^{i-j+1}{n\choose i}{n\choose j}$$
I am not sure how to proceed from here. I tried writing down a few terms but that doesn't seem...
Hi,
I have looked everywhere. Can someone please point me in the right direction for solving a system of ODEs with variable coefficients? I managed to solve such system with constant coefficients.
Homework Statement
1) Find the general solution of y''+ω02=Ccos3(ωx)
2) Show there exists two frequencies at which resonance occurs and determine them
The Attempt at a Solution
I've tried the method of undetermined coefficients, assuming a solution of the form y=(Acos(ωx)+Bsin(ωx))3...
Homework Statement
The task is to calculate the transmission probability when E<V0 given that the step potential barrier is of infinite length.
Homework Equations
So far it seems simple enough. For region I, where x<0, (we're assuming, as usual, that the particles/ waves are coming...
Most of this post is an overview. The actual question is at the end. Basically: If I am given crazy summations with lots of indices cycling through multiple matrices, is there a quick way I can implement this in Mathematica?
So, I am doing a little bit of research into nonholonomic...
Homework Statement
Problem:
Find the first eight coefficients (i.e. a_0, a_1, a_2, ..., a_7) of the power series expansion
y = ##Σ_{n = 0}^{∞}## [##a_n## ##x^n##]
of the solution to the differential equation
y'' + xy' + y = 0
subject to the initial-value conditions y(0) = 0, y'(0)...
Homework Statement
I have got this circuit:
I have to find coefficients k1 and k2, and time constants T1 and T2. Actually, we can see that T1 =R1*C1 and T2=R2*C2, but is it possible in this circuit or it's just theoretically time constants? I'm not sure, but as there is no amplifier in...
I have been trying to follow how the complex Fourier coefficients are obtained; the reference I am using is at www.thefouriertransform.com. However I am unable to follow the author's working exactly and wondered if anyone could help me see where I am going wrong.
First, I understand that the...
Homework Statement
A computer scientist has dropped a tiny pizza crumb onto a magnetic disk. Later, when it's turned on, the disk is rotating at 88 revolutions per second about its axis, which is vertical. The coefficients of kinetic and static friction between pizza crumbs and the disk are...
Using correlation coefficients as x in a regression??
I was reading an article in the Wall street journal and the author was using a rolling correlation coefficient, on a set of variables, as his predictor variable in a linear regression.
Basically it was a uni-variate linear regression , y=...
Hey! :o
$f(x)=\sum_{i=0}^{7}{a_ix^i}, g(x)=\sum_{i=0}^{5}{b_ix^i}$, $a_i, b_i$ are integer coefficients.
The prime $p$ divides $a_0, a_1, a_2, a_3, a_4$ but it does not divide $a_5, a_6, a_7$. $p$ divides also $b_0, b_1, b_2$, but it does not divide $b_3, b_4, b_5$.
$h(x)=f(x)g(x)$
Show that at...
Homework Statement
consider y'' + 2y' - 3y = 1 + xe^x, find the particular solution
The Attempt at a Solution
so
f(x) = 1 + xe^x
f'(x) =e^x + xe^x
f''(x) = 2e^x + xe^x
so it looks like my particular solution is going to have a constant term, an e^x term and an xe^x term,
so I can...
Homework Statement
The value of ((^n C_0+^nC_3+...) - \frac{1}{2} (^nC_1+^nC_2+^nC_4+^nC_5+...))^2 + \frac{3}{4} (^nC_1-^nC_2+^nC_4-^nC_5...)^2
The Attempt at a Solution
I can see that in the left parenthesis, the first bracket contains terms which are multiples of 3 and in the second...
Problem:
Let $\displaystyle (3x^2+2x+c)^{12}=\sum_{r=0}^{24} A_rx^r$ and $\dfrac{A_{19}}{A_5}=\dfrac{1}{2^7}$, then $c$ is
A)4
B)5
C)6
D)7
Attempt:
One way I know of to solve such a problem is by using the multinomial theorem but I am reluctant to use it here. It would take a lot of time to...
Homework Statement
"Suppose x[n] is a DT (discrete time) periodic signal with fundamental period N. Let us define x_{n}[n] to be x[n] for n ε {0, 1,2, ... , N-1} and zero elsewhere. Denote the Fourier transform of x_{n}[n] with X_{n}[e^jω]. How can one find the Fourier Series coefficients...
Hi,
I want a software that can generate aerodynamic coefficients (CD, CL, CY,Cl,Cm,Cn, etc)
I am aware of some specialized software (e.g. AVL, open source from MIT, LinAir Pro, commercial, etc).
But was wondering whether I can use 'common' software like AutoCAD Mechanical or Solidworks...
How to find the Glebsch Gordan coefficients by matrix form. Let's suppose we have a two spin 1/2 particles, we get that (check attachment 1). These are the corresponding coefficients the classic way. Now if I want find them the matrix way, where the matrix should be diagonalized. How do I...
Homework Statement
y'' + y = xsinx where y(0) = 0 and y'(0) = 1
Homework Equations
yc = C1sinx + C2cosx
The Attempt at a Solution
So my attempt includes the yc which undoubtedly is correct. I now try to solve yp
yp = Axsinx + Bxcosx
y''p = A(2cosx - xsinx) + B(-2sinx -...
A 1000 kg car is moving at 10 m/s, the car applies the brakes and begins to skid and leave a mark. the first 4 m of the surface has a coefficient of 0.35 and after that the coefficient of friction is 0.2. What is the total distance the car will slide when coming to rest?
Equations: F=ma...
Homework Statement
Prove by induction that for any positive integers a, b, and n,
(a choose 0)(b choose n) + (a choose 1)(b choose n-1) + ... + (a choose n)(b choose 0) = (a+b choose n)
Homework Equations
(x choose y) = (x!)/((x-y)!y!)
The Attempt at a Solution
I am able to do the...
Contemporary Abstract Algebra by Gallian
This is Exercise 14 Chapter 3 Page 69
Question
Let $G$ be the group of polynomials under the addition with coefficients from $Z_{10}$. Find the order of $f=7x^2+5x+4$ .
Note: this is not the full question, I removed the remaining parts.
Attempt...
Hello, I had a question about the method of undetermined coefficients for solving ODE's. I understand it is only useful for certain non-homogeneous functions, and those dictate specific guesses, but what if I had a sum or product of two valid functions, is the guess simply a sum or product of...
For a simple linear model:
\alpha+\beta\times x=y
If it is observed that y \in (-8.51,23.20) given x=4
The question is to give intervals of \alpha, \beta, which satisfy y \in (-8.51,23.20) given x=4.
Is this problem identifiable? Can it be found the unique intervals for \alpha...
Homework Statement
Compute the 2nd and 3rd Virial coefficients at 300K of Ar. Experimental parameters are mentioned in xlist and ylist below :)
Homework Equations
My professor has given a hit, which is as follows: "Use the data to determine the (z) compressability (sp?) and plot Z as a...
Homework Statement
In oppgave 1 a) I am supposed to show that the given equality is true (namely that the isoterm compressibility coefficient partial-differentiated with regards to temperature = isobar coefficient differentiated with regards to pressure multiplied by minus one)...
hey pf!
okay, so if you've studied PDEs you know the value of a Fourier series, and the difficulty of determining a Fourier coefficient. my question relates to finding this coefficient. briefly, i'll define a Fourier series as f(x)=\sum_{n=0}^{\infty} A_n\cos\frac{n\pi x}{L}+B_n\sin\frac{n\pi...
Homework Statement
x(t) = 4 for 0 <x<1 and 0 otherwise and this process repeats for all values including negative.
find X_0 and X_n
and find the first 6th harmonics of the Fourier series in cosine form
Homework Equations
The Attempt at a Solution
x_0 = 4/3
x_n =...
Greetings!
Going throught Ballentine Ch.4 and the derivation of transmission/reflection coefficients. The math seems fairly straightforward: assuming a particle in a piecewise-constant potential, the solution of the correspondent time-independent SE is a piecewise-exponential wavefunction in...
Homework Statement
Let ##f## be a ##2\pi## periodic function. Let ##\hat{f}(n)## be the Fourier coefficient of ##f## defined by
$$
\hat{f}(n)=\frac{1}{2\pi}\int_{a}^{b}f(x)e^{-inx}dx.
$$
for ##n\in\mathbb{N}##. If ##\overline{\hat{f}(n)}=\hat{f}(-n)## show that ##f## is real valued.
The...