Linear system Definition and 149 Threads

  1. paulmdrdo1

    MHB Another word problem involving a linear system.

    during its annual picnic, a company supplies lemonade for all employees and their families. the picnic committee has purchased twice as many pint jugs as quart jugs and 8 fewer gallon jugs than quart jugs. how many jugs of each type are there if 22 gallons of lemonade were purchased? (there 2...
  2. M

    Linear system of equations with parameters

    I have big problems with an equation system. It's been a long time since I worked with these type of problems and it would be wonderful if I could get an full solution of this or some similar problem. Decide for all real a and b, the number of solutions to the equation system. I...
  3. V

    Two-Degree-Of-Freedom Linear System: Eigenvalue problem

    I've found the characteristic equation of the system I'm trying to solve: $$ω^{4}m_{1}m_{2}-k(m_{1}+2m_{2})ω^{2}+k^{2}=0$$ I now need to find the eigenfrequencies, i.e. the two positive roots of this equation, and then find the corresponding eigenvectors. I've been OK with other examples...
  4. D

    How Do You Calculate Standard Deviation for Linear Combinations?

    I have attached the problem of interest. I think I am having trouble calculating the standard deviation for part a. D=A-B-C E(A)=10 E(B)=2 E(C)=2 sigma(A)=0.1 sigma(B)=0.05 sigma(C)=0.1 where sigma=standard deviation so to find SD...
  5. T

    MHB Can Complex Numbers Solve This Linear System?

    \mathbb C: (1+i)x + 2y = 3, 3x + (1i)y = 2i I don't know how to go about this, am I supposed to do addition of complex number? Please help.
  6. J

    How Can You Solve the Linear System Ax=b with Given Vectors a1 and a3?

    Let Ax = b be a linear system whose augmented matrix (A|b) has reduced row echelon form 1 2 0 3 1 ||-2 0 0 1 2 4 || 5 0 0 0 0 0 || 0 0 0 0 0 0 || 0a) Find all solutions to the system b)If a1= (1,1,3,4) and a3=...
  7. D

    MHB Graphically solving 2X2 linear system and finding the line through 2 points

    Basically I don't know anyone in real life that can help me with this, so I need help checking to see if my answers are correct :) PART A 1) Using a graphing utility solve the following system of linear equations. Round your answer to the nearest hundredth. y = -4x+2 x - 2y = 10 My answer: x...
  8. Z

    MHB Solve Linear System of ODEs | x(0)=x0,y(0)=y0,z(0)=z0

    I have another question so please help me. here we go -- Consider the following linear system of ODE : X’ = -x – y Y’ = x + 3y Z’ = 4x + 6y - z Note that the matrix of this system is exactly the same as A = [ 1 -1 0 1 3 0 4 6 -1 ] (a) Study the stability of the fixed...
  9. F

    Linear System with Parameter: Solutions and Homogeneity

    Homework Statement I have done this exercise, but I don't have a file with the solutions. COuld you please check it? Thank you in advance :) Given the following system: ##\lambda \in \mathbb{R}## ##x − z = \lambda## ##x + y + 2z + t = 0 ## ##y + 3z = ## ##x + z + t = 0## 1-find...
  10. N

    Is this a linear system of equations?

    Hello everyone! I have a question on whether a system of equations can be classified as linear. I have the following matrix: \begin{equation} \left[ \begin{array}{c} S_t(1) \\ S_t(2) \\ \vdots \\ S_t(\omega_N) \end{array} \right] = \begin{bmatrix} f(x_1, x_2, 1) & f(x_2, x_3, 1) & \cdots &...
  11. A

    Linear system of equations for a differential equation

    Solve the equation m\frac{d^{2}x}{dt^{2}} + c\frac{dx}{dt} + kx = (ax + b)^{2} + c^{2} for the constants m, c, k The right hand side a, b, and c are arbitrary digits. For me they are a = 2, b = 3, and c = 8. The problem recommends creating a linear system of equations for me to solve. This...
  12. N

    Trajectories of a linear system first order diff. equations

    In linear algebra, you can have systems of differential equations represented by matrices. What does a "trajectory graph" of such a system show, exactly? And how can you draw one? What's the difference between such a trajectory-graph and an ordinary slope-field for a single linear...
  13. R

    Linear system of differential equations with repeated eigenvalues

    Homework Statement X'=AXA=\left[\begin{matrix} 0 & 1 & 0 \\ -1 & 0 &0 \\0 & 0 & -1\end{matrix}\right] Homework Equations n/a The Attempt at a Solution The eigenvalues are -1, and \pm i. I also can see that the matrix A is already in the form A=\left[\begin{matrix} \alpha & \beta & 0 \\...
  14. Fernando Revilla

    MHB Arran's question at Yahoo Answers (linear system)

    Here is the question: Here is a link to the question: How do you solve a pair of coupled differential equations where the matrix of coeffs has complex Eigenvalues? - Yahoo! Answers I have posted a link there to this topic so the OP can find my response.
  15. M

    Is the Linear System inconsistent?

    Hey guys, I'd assume that this will be a very easy answer. I need to clarify what is an inconsistent linear system. I've worked out my matrix and have achieved this form: x+0y+z+0w=0 0x+0y+z+w=0 0x+0y+0z+w=0 I know that an inconsistent linear system has no solution i.e 0=1. This is...
  16. N

    What does the Eigenvalue of a linear system actually tell you?

    I know that the eigenvalue of a linear system is a scalar such that Ax=λx. I know many ways to find the eigenvalue of a linear system. But I'm pulling my hair out trying to figure out what it is actually telling me about the system. Can anyone give me a non-technical straight up answer on why...
  17. B

    What Happens When All Equations in a Homogeneous Linear System are 0=0?

    Homework Statement In the proof of Lemma 3.6, what happens if there are no non-‘0 = 0’ equations? Homework Equations 3.6 Lemma For any homogeneous linear system there exist vectors B1,...,Bksuch that the solution set of the system is {c1 B1+..+ckBk|c1,..ck εR} where k is the number of...
  18. L

    ODE Linear System Complex Eigenvalues

    Homework Statement Solve the following systems by either substitution or elimination: dx/dt = y dy/dt = -x + cos(2t) Homework Equations I know the solution is: x(t) = c_1cos(t) + c_2sin(t) - 1/3cos(2t) y(t) = -c_1sin(t) + c_2cos(t) + 2/3sin(2t) The Attempt at a Solution x' = [ 0 1; -1...
  19. X

    How Does the Transformation Matrix P Convert a Linear System to Canonical Form?

    Hi there, I have a linear algebra question relating actually to control systems (applied differential equations) for the linear system {\dot{\vec{{x}}} = {\bf{A}}{\vec{{x}}} + {\bf{B}}}{\vec{{u}}}\\ \\ A \in \mathbb{R}^{ nxn }\\ B \in \mathbb{R}^{ nx1 }\\ In class, we...
  20. fluidistic

    Linear system, input/output signal

    Homework Statement I'm stuck on the following problem: A linear system has an output of G(\omega ) e^{-i \omega t} to an input signal of e^{-i\omega t} where omega is arbitrary. If the input signal has the form f(t) = \begin{cases} 0 \\ e^{-\lambda t} \end{cases} where lambda is a constant...
  21. B

    Constraint on a linear system?

    The question goes like this. Among all solutions that satisfy the homogeneous system x + 2y + z = 0 2x + 4y + z = 0 x + 2y − z = 0 determine those that also satisfy the nonlinear constraint y − xy = 2z I know that one of the solutions [0,0,0] but I'm not sure how to find the others. I row...
  22. 1

    Linear System - Network Flow Matrices

    Homework Statement Consider the network of streets with intersections a,b,c,d and e below. The arrows indicate the direction of traffic flow along the oneway streets, and the numbers refer to the exact number of cars observed to enter or leave a,b,c,d and e during one minute. Each xi denotes...
  23. A

    MHB Determining Basic and Free Variables in a Linear System

    Find the general solution to the following system of equations and indicate which variables are free and which are basic. Putting it in augmented matrix form to start we have: 1 -1 -1 4 | -3 1 0 -1/2 3 | -1 1 1 0 2 | 1 Now performing the following fundamental row operations: R1<-->R2...
  24. A

    How Do You Solve This Linear System and Identify Free and Basic Variables?

    Find the general solution to the following system of equations and indicate which variables are free and which are basic. x_1 + 4x_4 + 3 = x_2 + x_3 x_1 + 3x_4 + 1 = \frac{1}{2}x_3 x_1 + x_2 + 2x_4 = 1 Putting it in augmented matrix form to start we have: 1 -1 -1 4 | -3 1 0 -1/2...
  25. F

    Translating a linear system to have critical points at the origin?

    So suppose you have a nice simple linear system dx/dt = a1x + b1y + c1 dy/dt = a2x + b2y + c2 and a critical point (x0, y0) ≠ (0,0). If you want to analyze the stability in the usual linear method, then I assume there should be some transformation to have the critical point at the origin. So is...
  26. I

    Unsure Which Method To Solve Linear System Was Used

    Hi, I have a problem from a textbook on control systems along with the solution, but I'm not certain how the answer was derived. The only thing I'm confused by is the method by which the system of equations was solved, which appears to be something similar to, but not quite, Cramer's rule...
  27. I

    Solving Linear System of Equations: Elimination

    Homework Statement A general system of linear equations is ax+by=e cx+dy=f where a,b,c,d,e,f are constant values. a)Use elimination to solve for x and y in terms of a,b,c,d,e,f. b)Are there any values that a,b,c,d,e,f cannot have?The Attempt at a Solution For part A, I got x=(e-f)/(a-c)...
  28. B

    Finding Inverse from Known Linear System

    Hello All: Suppose I have a completely known linear system: A*x=b. I know the matrix A, and an x and the associated RHS vector b (and it is non-trivial). Is there some tricky way to directly determine the inverse of A without performing an inversion by typical means (Gauss elimination, LU...
  29. F

    Linear system of equations and its solution(s)

    Hello Forum, a system of linear algebraic equations can have 1 solution, zero solutions, or infinite solutions. Can it ever have multiple, finite solutions? Why not? when the system has infinite solutions, are the equations representing all the same identical equation, i.e. they are...
  30. J

    Linear System Solutions for a Unique Value of a | Math 115 Homework

    Homework Statement I'm trying to solve #1 here: http://www.student.math.uwaterloo.ca/~math115/Exams/M115.FE.pdf The problem is: The Attempt at a Solution (a) At a=2, the slope is the same. I figure any value but 2 gives unique solutions. But I don't know if this is right. (b) At...
  31. L

    Solving linear system of congruences

    Homework Statement Solver for n and m in the following equations: 2n + 6m \equiv 2 (mod 10) n + m \equiv -2 (mod 10) Homework Equations The Attempt at a Solution I've worked through several of these problems prior, including ones in the book and most take the form: 2n + 3m = 3...
  32. O

    Existent solution to the linear system Ax=b

    Suppose that the linear system Ax=b is given for some symmetric A, and it is known that vector c spans the null-space of A. How could one formally show that if b is not orthogonal to c, the solution to the system Ax=b does not exist? To remind you, the null-space of A contains all vectors u...
  33. K

    MHB Algebraic Structure to solve a linear system of 2 variables?

    Hi folks, I'm hoping to get your opinions about something. If i were given two linear equations and needed to solve for x and y using the methods of "substitution" and "elimination", what algebraic structure should i use? I can solve the systems just fine, but I'm trying to "explain" each step...
  34. K

    When solving a linear system for x and y, am i in a group? ring? field?

    Hi everyone, I'm currently taking an abstract Algebra course and need a little guidance with an analysis of solving a system of linear equations. We are given two linear equations and need to solve for x and y using the method of "substitution" and again using "elimination". However, we must...
  35. B

    Solving A Non Linear System With a Cube

    Homework Statement Find all solutions for the following system: X^2-xy+2y^2=8 X^3-xy^2=0 2. Questions What steps could I take to solve this? I've tried just about everything I can think of. I don't know if I should solve the cubic equation for a variable and plug it in or what. I am...
  36. M

    Conditions on overdetermined linear system to be consistent?

    Homework Statement Homework Equations An overtdetermined system - If m > n, then the linear system Ax = b is inconsistent for at least one vector b in ℝ^n. The Attempt at a Solution If m > n (more rows than columns), in which case the column vectors of A cannot span ℝ^m (fewer vectors...
  37. A

    MHB How is the Steepest Descent Formula Used to Solve Linear Systems?

    Steepest descent for linear system what is the formula of steep descent to solve linear system can you give me a link
  38. H

    Linear wave equation vs. linear system

    Hi, I have a general question about linear wave equation: Is solving the linear wave equation is equivalent to compute the output of a linear system where source is the input? Thanks in advanced! Chao
  39. S

    Iterative methods to solve linear system of equations

    Show that if (Spectral radius) ρ(M)≥1 then there are x0 and c such that the iteration xk+1 = Mxk+c fails to converge I am very lost on how to solve this problem. All the literature I have been able to read up proves the converse of the statement. I am unable to crack this. Show that if A is...
  40. S

    DSP - Differential Equation for linear system H

    Hello. I need to find a differential equation for a linear system, H, which is characterised by the impulse response h(t) = e-2t, where t denotes time. But I am not sure how to go about this. Would anyone be able to point me in the correct direction? Thanks in advance. Seán
  41. T

    Linear system of exponential equations

    Homework Statement Consider the system of equations \begin{eqnarray*} e_1 &=& Ak^p + Bh^q \\ e_2 &=& A(k/2)^p + Bh^q \\ e_3 &=& Ak^p + B(h/2)^q \\ e_4 &=& A(k/2)^p + B(h/2)^q \end{eqnarray*} Suppose that the e_i are known, as well as k and h. Find A, B, p, and q. Homework...
  42. L

    Can This Linear System Be Considered Stable?

    Homework Statement Determine the stability of the following linear system y(n) = 0.5x(n) +100x(n-2) - 20x(n-10) Homework Equations x(n) = 0.5\delta(n) S=\sum^{\infty}_{k=0}\left| h(k)\right| The Attempt at a Solution Z \left\{ 0.5x(n) +100x(n-2) - 20x(n-10) \right\} Z...
  43. fluidistic

    Non linear system of 4 equations, how to solve it?

    Homework Statement I'm stuck in a problem where I deduced a set of non linear equations. I must solve for A_0, A_1[/itex], x_0 and x_1. I just don't know how to tackle this. The system is: A_0+A_1=\frac{2}{3} A_0x_0+A_1x_1=0 A_0x_0^2+A_1x_1^2=\frac{2}{5} A_0x_0^3+A_1x_1^3=0...
  44. A

    Reproduce a solution set to a linear system with 2 equations and 8 variables

    Homework Statement Show how the following solution set: [x1,x2,x3,x4,x5,x6,x7,x8]^T =[1,-1,0,0,0,0,0,0]^T, [0,-1,1,0,0,0,0,0]^T,[0,0,0,1,-1,0,0,0]^T,[0,0,0,-1,0,1,0,0]^T,[0,0,0,0,-1,0,1,0]^T,[0,0,0,0,0,-1,0,1] is obtained from the two linear equations x1+x2+x3-x4-x5-x6-x7-x8=0 and...
  45. G

    Find a linear system of equations from the word problem?

    The problem: "A commercial customer orders 81 gallons of paint that contains equal amounts of red paint, green paint, and blue paint - and hence, could be prepared by mixing 27 gallons of each. However, the store wishes to prepare this order by mixing three types of paint that are already...
  46. H

    Finding the Normal Vector for a Plane in 3D Space - Is My Approach Correct?

    1) Find a vector equation for the plane in R3(3D) with scalar equation 2x − 3y + z = 5 . First,I find three points on the plane and then I used one point as a fixed point in order to find two vectors on the plane by using two other points. Then, I tried to test whether the two vectors are...
  47. C

    Testing Stability of Linear System Fixed Points

    Homework Statement Classify the fixed points of the following linear system and state whether they are stable or unstable \dot{x}=x + y \dot{y} = x + 3y Homework Equations The Attempt at a Solution Fixed point at dy/dx = 0/0. Therefore fixed point = (0,0) How does one test...
  48. S

    Is the Given Vector the General Solution of the Nonhomogeneous Linear System?

    Homework Statement Verify that the given vector is the general solution of the corresponding homogeneous system and then solve the nonhomogenous system. Assume that t>0. tx' = |2 -1|x + |1- t^2| |3 -2| |2t | General solution: x = c1| 1|t + c2| 1|t^-1 | 1|...
  49. M

    Solve linear system using augmented matrix

    Homework Statement Solve using an augmented matrix: 3r-2s+4t=6 2r+3s-5t=-8 5r-4s+3t=7 2. The attempt at a solution [3 -2 4 | 6] => [1 0 0 | x] [2 3 -5 |-8] => [0 1 0 | y] [5 -4 3 | 7] => [0 0 1 | z] I have successfully used 2x2 augmented matrices, but with 3x3 it seems like there are...
  50. H

    General Solutions to a Linear System

    According to this, http://upload.wikimedia.org/math/5/8/2/582b41cd88284564c46e711cbbca55fa.png http://en.wikipedia.org/wiki/System_of_linear_equations#Homogeneous_systems A general solution to some linear system is a particular solution (P) + a homogeneous solution (H) My question: is...
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