Linear Definition and 1000 Threads

Homework Statement I am having trouble proving if the equation i have found for number 1 is correct. I have posted my solution to get back to the main problem in the first photo below. For number 2 I am having trouble isolating for 1 y(x). Did i do the integration and setup properly?Homework...

How can I choose the characteristic linear dimension? For example in pipe it is its diameter, but on a surface is the length, on a flat plane it can be measured as 4A/P. I was having problems determining the characteristic linear dimension for a diffusion problem in a "rectangular" pipe. I don't...

First off I'm not an engineer nor do I have a electronics background. I have an old Linear (HP 6284A Power Supply). I would like to be able to display Hz/CPS. I need to measure the speed of a tattoo machine. (basically two coils that make and break connection through out its use. From what...

hey everyone just started university and the jump i feel is huge from a level and was just wondering if you guys knew of any books that had linear algebra and/or several variable calculus in them but displayed and explained stuff in a clear simple way? or if anyone has any websites that do the...

Homework Statement "Show that a solution of the homogeneous PDE ##au_x+bu_y+cu=0## cannot be zero at one, and only one point in the plane." My interpretation of this is that ##u(x,y)## is zero everywhere on the plane except on that point ##(x_0,y_0)##. Homework Equations ##w=bx-ay## ##z=y##...

I've started self-studying quantum mechanics. It's clear from google searching and online Q.Mech lectures, I'll need to understand linear algebra first. I'm starting with finite-dimensional linear algebra and Hoffman, Kunze is one of the widely recommended textbooks for that. I need help...

Homework Statement given that X is an n × p matrix with linearly independent columns. And $$X^∗ = XA$$ where A is an invertible p × p matrix. a) Show that: $$X^*{({X^*}^TX^*)^-}^1{X^*}^T = X{(X^TX)^-}^1X^T$$ b) Consider two alternative models $$M : Y = Xβ + ε$$ and $$M^∗ : Y = X^∗β ^∗ +...

Homework Statement Determine the values of a for which the following system of linear equations has no solutions, a unique solution, or infinitely many solutions. You can select 'always', 'never', 'a = ', or 'a ≠', then specify a value or comma-separated list of values. x1−2x2+2x3 = −1...

Hello! I was introduced in the Real Analysis class the notion of ordered set. I am not sure I understand the concept of linear and non-linear ordering. Can someone explain this to me? Thank you!

1. Problem Recall that we defined linear equations as those whose solutions can be superposed to find more solutions. Which of the following differential/integral equations are linear equations for the function u(x,t)? Below, a and b are constants, c is the speed of light, and f(x,t) is an...

In this paper on the history of functional analysis, the author mentions the following example of an infinite system of linear equations in an infinite number of variables ##c_i = A_{ij} x_j##: \begin{align*} \begin{array}{ccccccccc} 1 & = & x_1 & + & x_2 & + & x_3 & + & \dots \\ 1 & = & &...

Homework Statement Suppose we have a potential such that $$ V = \left\{ \! \begin{aligned} 0 & \text{ if } x<0\\ \mathcal{E}x & \text{ if } x>0, x<L\\ \mathcal{E}L & \text{ if } x>L \end{aligned} \right. $$ for some electric field ##\mathcal{E}##. I'm trying to find the transmission...

A pet mouse sleeps near the eastern edge of a stationary, horizontal turntable that is supported by a frictionless, vertical axle through its center. The mouse wakes up and starts to walk north on the turntable. Is the momentum of the system constant? i understand that the initial momentum is...

I am going to have two slots available this year for electives and I want to use one of them for Astronomy. For the other, I am struggling to decide between Linear Algebra or Computer Science (CIS 210 at my university) which focuses on Python programming. If I can only choose one, which is more...

Homework Statement Assume two masses m1' and m2' are moving in the positive x-direction with velocities v1' and v2' as measured by an observer in S' before a collision. After the collision, the two masses stick together and move with velocity v' in S'. Show that if an observer in S' finds...

Hey. I am working with OLS regression. First I run 2 regression operations with each having just one independent variable. Then I run another regression using both the independent variables from the first two regressions. If the explanatory "power" (R^2) in the third regression was to be the sum...

Hi all, Yet another question: if the universe is finite, then linear momentum should be quantized (I assume in a similar manner to an infinite potential well since there are boundary conditions). My question is, then, if one computes a value for ##\Delta p## (momentum variance), is the variance...

Homework Statement An infinitely long line of charge has linear charge density ##λ=4.00_{10^{−12}} \frac{C}{m}##. A proton (mass ##m_p=1.67_{10^{-27}}kg##, charge ##e=1.602_{10^{-19}}C##) is ##r_a=0.18m## from the line and moving directly toward the line at ##v=1000\frac{m}{s}##. Homework...

G'day guys So I currently have a 2x 8" stoke 150lbs dynamic force actuators with a maximum current draw of 5A. The exact one is the FA-PO-150-12-XX in the link below: https://www.firgelliauto.com/products/feedback-rod-actuator The load I have on it causes the actuators to draw almost its'...

Homework Statement Q. Let A be an m by n matrix. Assume that the equation Ax=b is consistent for some b≠0 in Rn. Moreover, assume that Ax=b has a unique solution. Does the equation Ax=0 have a non-trivial solution? Is it possible to find a vector V in Rm so that the system Ax=V has infinitely...

Imagine that you own a grove of orange trees, and suppose that from past experience you know that when 100 trees are planted, each tree will yield about 240 oranges per year. Furthermore, you've noticed that when additional trees are planted in the grove, the yield per tree decreases...

Hello, its been a while since I have taken linear algebra and I am having trouble understanding what a target vector is. I need to solve a system of linear equations in matrix form using back substitution and with different target vectors. I don't have a problem with back substitution, but I...

Hi there, I attached an image of a basic linear motor. I'm a little confused if I use the right hand rule or left hand rule. I did it both ways and I think the left hand rule is the only rule that allows for a force being applied to the right. I assume the current is going down rather than...

Homework Statement "A straight, nonconducting plastic wire ##x=9.50_{10^{-2}}m## long carries a charge density of ##λ=1.3_{10^{-7}} C/m## distributed uniformly along its length. It is lying on a horizontal tabletop. If the wire is now bent into a circle lying flat on the table, find the...

Lavolta BPS 305 0-30V and 0-5A. I was showing a young lad how you can energise a car ignition coil and get a spark on the output, and that this effect can be improved by adding a cap in parallel which forms a crude LC oscillator etc when the unit died. Silly, I know, but we got a bit carried...

Homework Statement Homework EquationsThe Attempt at a Solution Because of the external magnetic field ##\vec B_0 ## , a uniform magnetization will be in the direction of external magnetic field. Because off this uniform magnetization, there will be a uniform magnetic fied in the direction of...

Hi everybody. I need to learn how to solve this kind of equation by decomposing y in a serie of functions. All the examples I have seen are of homogeneous functions. I would be extremely thankfull if someone pointed me to some text in which this is done-explained. Thanks for reading.

As per my understanding, a linear equation with two variables form a line segment (ax=by+c or ax+by=c) and linear equation with three variables form a plane (ax=by+cz+d or ax+by+cz=d). Am I right? And if I am right, does an equation with four variables form a cube?

Hi All, In my work I would like to solve a thousands of moderate size systems of linear equations, parallelly. The uniquum in my problem is that, I am not interested in the whole solutions of the systems, but only several elements of the solution vectors are interesting. To be more strict: Let...

Charge moving in constant linear velocity does not produce magnetic field... If not, please provide an explanation...

Can a sphere with a frozen - in uniform polarization ## \vec P ## be considered a linear dielectrics? Following the definition of dielectrics given in Griffiths: The electric field inside the sphere, ## \vec E = \frac {-P}{3 \epsilon_0} ## So, ## \vec P ≠ ε_0 χ_e \vec E ## as ## ε_0 χ_e##...

I am sizing a linear actuator to build a BMX gate. Please see the drawing below. I have a metal gate that is 20" tall and 9.5' wide. It will be steel and weigh approximately 150lbs. I am mounting the rear of the linear actuator on a clevis 8" off the ground. The front will be mounted with...

I have heard that chaos exists in all dynamical systems.Does this mean that chaos exists in circuits with linear elements too?Which software is best for analyzing chaos in electric circuits?

How would the rotary motion of a robot / exoskeleton arm be converted into linear motion so that the arm can move objects and lift weights in a conventional manner, such as when people are weight lifting in a gym?

I know both are different courses, but what I mean is, will a proof based Linear Algebra course be similar to an Abstract Algebra course in terms of difficulty and proofs, or are the proofs similar? Someone told me that there isn't that much difference between the proofs in Linear or Abstract...

Homework Statement If A is an n x n matrix over R such that A^3 = A + 1, prove that det(A) > 0 . Homework EquationsThe Attempt at a Solution So, what I've done is factor the expression to get A(A+1)(A-1) = 1, then taking the determinant of both sides, I get det(A)det(A+1)det(A-1) = 1. I...

Homework Statement Given $$u''(x)+\lambda u = 0\\ u(-1)=u(1)=0.$$ If ##\lambda_0## is the lowest eigenvalue, show that ##4 \lambda_0 = \pi^2##. Homework Equations $$\lambda_0 = glb\frac{(L(u),u)}{(u,u)}$$ where ##glb## denotes greatest lower bound and ##L## is the Sturm-Louiville operator. I...

Homework Statement Hello to everyone that's reading this. :) For this linear least-squares regression problem (typed below and also), I correctly find the value of g (which is what the problem statement wants to have found), but I was curious about the value of ##a_0## (and that's what this...

Homework Statement "Show that every subspace of ##ℝ^n## is the set of solutions to a homogeneous system of linear equations. (Hint: If a subspace ##W## consists of only the zero vector or is all of ##ℝ^n##, ##W## is the set of solutions to ##IX=0## or ##0_vX=0##, respectively. Assume ##W## is...

Homework Statement "Find ##S_\alpha## where ##S: M_{2×2}(ℝ)→M_{2×2}(ℝ)## is defined by ##S(A)=A^T##. Homework Equations ##A^T=\begin{pmatrix} a_{11} & a_{21} \\ a_{12} & a_{22} \end{pmatrix}## ##\alpha= \{ {\begin{pmatrix} 1 & 0 \\ 0 & 0 \end{pmatrix}, \begin{pmatrix} 0 & 0 \\ 1 & 0...

Homework Statement "Determine whether the function ##T:M_{2×2}(ℝ)→ℝ## defined by ##T(A)=det(A)## is a linear transformation. Homework Equations ##det(A)=\sum_{i=1}^n a_{ij}C_{ij}## The Attempt at a Solution I'm assuming that it isn't a linear transformation because ##det(A+B)≠det(A)+det(B)##...

Hey all, I'm currently working on my CS degree with a mathematics minor. After this Fall, I will only have one more course to take to finish my minor. I'm debating between Linear Algebra and Deterministic Operations Research. I do have other options, but these seem to be most applicable to CS...

I have some data that I want to do simple linear regression on. However I don't have a lot of datapoints, and would like to know the uncertainty in the parameters. I.e. the slope and the intercept of the linear regression model. I know it should be possible to get a prob. distribution of the...

Homework Statement Use definition (1) to determine if the functions ##y_1## and ##y_2## are linearly dependent on the interval (0,1). ##y_1(t)=cos(t)sin(t)## ##y_2(t)=sin(t)## Homework Equations (1) A pair of functions is said to be linearly independent on the interval ##I## if and only if...

Homework Statement Linear Algebra Problem: Solving for Euler between two ordered bases I've got a problem I need to solve, but I can't find a clean solution. Let me see if I can outline the problem somewhat clearly. Okay, all of this will be in 3D space. In this space, we can define some...

Cross-posted on SE.DS Beta. I'm just doing a simple linear regression with gradient descent in the multivariate case. Feature normalization/scaling is a standard pre-processing step in this situation, so I take my original feature matrix $X$, organized with features in columns and samples in...

Imagine that you own a grove of orange trees, and suppose that from past experiences you know that when 100 trees are planted, each tree will yield about 240 oranges per year. Furthermore, you've noticed that when additional trees are planted in the grove, the yield per tree decreases...

Hi all, I'm stuck on progressing a problem i have received some feedback around as detailed below. I would greatly appreciate some assistance, and thank you in advance for your time and contributions. So i have a linear system: Which is row reduced to: I have identified that the system has...

Homework Statement Consider a straight line segment of 3L and with a linear charge density λ. Determine the electric field, E, of at point P, which is a point within the segment and along the axis. (figure attached) Homework Equations dE=kdQ/r^2 The Attempt at a Solution I attempted solving...

Homework Statement Let ##T:M_2 \to M_2## a linear transformation defined by ##T \begin{bmatrix} a&b\\ c&d \end{bmatrix} = \begin{bmatrix} a&0\\ 0&d \end{bmatrix}## Describe ##ker(T)## and ##range(T)##, and find their basis. Homework Equations For a linear transformation ##T:V\to W##...