Linear equation Definition and 131 Threads

  1. J

    Diff. eq. solve linear equation

    Homework Statement Solve the following differential equations. 3xy'+y=12 Homework Equations I believe this is a linear equation problem. So I believed to have solved it, however I am not sure if I have done so correctly. The Attempt at a Solution
  2. J

    Differential equation to homogenous linear equation.

    can this equation y, = ycot(x) + sin(x) be reduced to a homogenous linear format? If yes, how? I tried the usual y=xv and the x=X+h, y=Y+k but doesn't seem to be working. Any ideas? Thanks just realized its in the form of dx/dy+Px=Q so I solved it by multiplying on B.S. by e∫Pdx and the...
  3. H

    Variation of parameters- 2nd order linear equation

    Homework Statement solve 4y''-4y'+y=16et/2 Homework Equations v1= -∫ y2g/w v2= ∫ y1g/w The Attempt at a Solution http://imgur.com/gxXlfdH the correct answer is 2t^2 e^(t/2) instead of what i have though, i am not sure what i am doing wrong?
  4. R

    Comp Sci Fortran programming to solve linear equation for ode

    Fint the exact solution of the system dy/dt = -15y-25z dz/dt=-47y-85z with inital condition y(0)=2, z(0)=5 either by writing the equation in matrix form as dx/dt =AX where x=(y z) and diagonalising the matrix A, or otherwise. Using fortran programming with second order adam bashforth...
  5. P

    Solving a Linear equation with 3 unknown variables

    3x + 4y + 2y = 1 The solutions for x, y, and z is { ( (1/3-4l-2m) | 3l | 2m ) }, where y = l and z = m. I've tried this method, presupposing y = l and m = z, then it came to I. l = (1 - 3x -2m) / 4 II. m = (1 - 3x -4l) / 2 If I try to put in either (I) or (II) to x, it would come...
  6. F

    MHB Why Isn't y Treated as a Constant in the Product Rule?

    Find the gernal solution of cosx\frac{dy}{dx}+(sinx)y=1 So \frac{dy}{dx}+\frac{sinx}{cosx}y=\frac{1}{cosx} \frac{dy}{dx}+tan(x)y=csc(x) therefore P(x)=tan(x) Let \mu (x) = e^{\int P(x) dx}=e^{\int tan(x) dx} =\frac{1}{cosx} multiply both sides of the equation by integrating factor...
  7. D

    Nonlinear Equation: Solve x,y,z

    Homework Statement Solve x,y and z from \frac{y+z}{a}= \frac{x+z}{b}=\frac{x+y}{c} = xyz wit a,b,c not equal to zero. Homework Equations The Attempt at a Solution I have no idea how to start. I've tried several things but it seems like I'm missing something. I did find the trivial solution...
  8. PsychonautQQ

    Find Linear Equation of a plane

    1. The problem estatement, all variables and given/known data Find the Linear equation of a plane passing through the origin and points (6,2,2) and (5,-1,1) Homework Equations Linear equation of a plane takes the form ax+by+cz+d = 0 The Attempt at a Solution So I believe I can...
  9. D

    System of linear equation in term of column vector

    Hello! The following system of linear equations has been expressed in term of column vector in the following. . How can I express the system of linear equations in term of row vector? In addition, What is the field of scalars? I would request to explain it. Thanks in advance.
  10. karush

    MHB A linear equation in 3 variables

    write a linear equation in 3 variables that is satisfied by all 3 of the given ordered triples $(1,1,1), (0,2,0), (1,0,0)$ the examples in book are all on the $ax+by+cz=d$ equation but with just ordered triples there is no $d$ or can it be found from them... otherwise I would solve this by...
  11. S

    Solving this system of linear equation.

    hey good people, I'm having a problem with how to solve a problem I'm having. first of all, I am working on an isometric game, and align my tile's are layed out like so: so, here's the problem: the numbers are arranged in how the tile's are layed out in memory, however, i want to be...
  12. K

    MHB Help solving a linear equation in one variable

    15+1/2=0.60(20x)
  13. M

    PDE Linear Equation Q: Homogeneous vs Nonhomogeneous

    My questions concerns the information in the document. I highlighted the portion that is confusing me and a sample problem at the bottom. Question: Look at the equation 2.2.4 in the document. When I set the function u equal to zero the equation becomes 0 = 0 + 0 + f(x,t) or f(x,t) = 0. Now...
  14. X

    I can't understand this linear equation at all

    Homework Statement Alright... 3x - 6y = 0, Graph the linear equation, finding it's intercepts. Homework Equations I've tried solving it by putting 0 in for x / y, and I've also tried putting -2 in for x / y, so that y = 2 when I move it over, and the system for my college...
  15. A

    Linear equation (differential equations) problem

    Homework Statement Solve: dP/dt + 2tP = P + 4t - 2 The Attempt at a Solution I've done a couple of these but I'm not sure how to start with this one... First I have to put it in standard form right? dP/dt + P(2t - 1) = 4t - 2 Then obtain the integrating factor by...
  16. B

    Solve Linear Equation: Mother's Age w/ 2 Sons

    Homework Statement The age of a mother is twice the sum of ages of her 2 sons. 5 years later the mother will be 20 years older than the sum of ages of her sons. What age is the mother today? Homework Equations The Attempt at a Solution M - mother ; S1 = son1 ; S2 = son2. S = S1...
  17. icesalmon

    Question about linear equation

    Homework Statement Show that if the linear equations x1 + kx2 = c and x1 + lx2 = d have the same solution set, then the equations are identical ( k = l, c = d) The Attempt at a Solution since the two equations have the same solution set, they are equal for every value of c and d so x1 +...
  18. H

    Is x1+x2=x3+x4 a linear equation?

    Is it? Personally, I think it is since the max power on any unknown is 1, no trig function, no product of unknowns etc. Also could the above mentioned linear equation form a linear system ? I don't think so (cause we always need at least two separate linear equations to form a linear system) but...
  19. C

    MHB Is a Line Parallel to the Y-Axis a Function?

    Hello guys, i hv doubt in this question: "1-Mark the point Q, such that the line through P (1, -2) and Q is perpendicular to the x-axis (the horizontal axis) so that the point Q to point P is equidistant from the axis x. Find the equation of the line."If the line be perpendicular of the X...
  20. N

    MHB Generating a linear equation from the given expression

    Good Day, I need some help with the following problem. I do not know how to generate a linear equation connecting y and x from the expression below as the 4 seems to complicate things \(3^y = 4(3^{x-2}) - 1\) Could some one please care to give me some advice? Thanks in advance.
  21. D

    Linear Algebra: Linear Equation System -> Parameter Form

    Homework Statement Consider the following linear system of equations: x1+2x3-5x4 = 0 x1 + 4x2 +4x3 – 5x4 = 10 x1 + 2x2 + 3x3 – 5x4 = 5 4x1 + 2x2 + 9x3 – 20x4 = 5 b) Solve the equation system with the Gaussian method. c) The solution set describes a plane. Specify it in the parameter...
  22. D

    Interval Restriction on Solutions to First Order Linear Equation

    I took a picture of a simple problem from my Diff Eq book. It is split up into two pictures for better resolution. In summary, ty'+2y=4t^2 (1) Has the solutions, y=t^2+C/t^2 (2) So, equation (1) has infinite solutions of the form of (2). But imposing the initial...
  23. A

    How Can You Maximize a Linear Equation with Multiple Constraints?

    Hello, I want to maximize a linear equation: 4*a + 8*b + 7*c + 5*d + 9*e with the following constraints: 0<=(4*a + 8*b + 7*c + 5*d + 9*e)<=1 0<=a<=100; 0<=b<=100; 0<=c<=100; 0<=d<=100; 0<=e<=100 Can I solve this problem using linear programming? Is there are any other method to do it...
  24. S

    Solving a linear equation with a cross product

    Homework Statement Suppose v is a vector satisfying: \alpha v + ( a \times v ) = b For \alpha a scalar and a, b fixed vectors. Use dot and cross product operations to solve the above for v. Homework Equations The unique solutions should be: v=\frac{\alpha^{2}b- \alpha (b \times a) + (b...
  25. T

    Satisfy the Differential Equation - Linear Equation

    Homework Statement Find the function satisfying the differential equation: dy/dx - 3y = 6e^(5x) with y(0) = -6 Homework Equations I believe this is Linear, so it is dy/dx + P(x)y = f(x) The Attempt at a Solution I chose -3y to be P and used it to obtain integrating factor e^(-3x). I...
  26. L

    Exponential functions - converting a linear equation

    Homework Statement Ok, so I have an unknown exponential function: y1 = f1(t) By measuring the values of t and yi, a linear connection is generated between Yi (=log (yi)) and t: Yi = Ait + Bi. A1 = -2.12 B1 = 1.96 Problem 1: Describe f1 in the following matter: y1 = f1(t) = Ceλt...
  27. P

    Solutions to Cubic equation that dont diverge when reduced to linear equation

    I am currently trying to solve for the metric function for a black hole in adS space with quasi-topological gravity. The details aren't too important, but the point is that I have to solve for a cubic at one point, and choose the correct solution, which is the one that reduces to a linear...
  28. C

    Is this really a linear equation?

    Homework Statement The question is asking whether or not the given equations are linear. I am unsure whether this equation (below) is linear or not? x1 + 5x2 - sqrt(2x3) = 1 The Attempt at a Solution My initial answer is that it is not due to the fact that a linear equation does...
  29. T

    Showing Linear Subspace & Affine Subspace of Vector a in R^n

    Let a be a fixed nonzero vector in R^n a. Show that the set S of all vectors x such at ax=0 is a subspace of R^n. b. show that if k is a nonzero real number, then the set A of all vectors x such that ax=k is an affine subspace of R^n, but not a linear subspace.how do i even show this.. I am so...
  30. T

    Linear equation, span, vectors, linear systems of equations

    show that S and T have the same span in R^3 by showing that the vectors in S are in the span of T and vise versa. S= {(1,0,0), (0,1,0)} T= {(1,2,0), (2,1,0)}im a little confused on how to start off on this problem.. help?!
  31. A

    Mathematica Solution of linear equation using Mathematica

    Please anyone can help me for finding solution of linear equation by using mathematica, for example take us equations as, 9x+10y+7z+18 w=8 3x-3y-8z+88 w=0 12x+9y-17z-14w=2 x+y-2z+w=0 Infect I have to use this thing in my code which will be good by using this thing,,, Any...
  32. A

    Solving First-Order Linear Equation with Reversed Roles

    Hi, I have a differential equation that I just can't seem to solve. Now here's the deal: I'm sure there are advanced methods that would easily solve this equation, but the equation is in the chapter on First-Oder Linear Equations, so it shouldn't be anything fancy. There's even a hint: it...
  33. B

    Solution to a linear equation of matrices

    Hi, How can I solve the equation below for M. G*inv(A+G'*inv(M)*G)*G'+F+M=0 G' is the transpose of G and inv(.) is the inverse of a matrix. Thanks
  34. N

    Statistics: linear equation comparision question

    Hello Everyone, I was wondering if there is a statistical method to compare two linear equations. I have one "nominal" equation y1=a1*x+b1 and one equation found using linear regression on a data set, y2=a2*x+b2. I know I can just "look" and compare the slope and intercept values but it...
  35. O

    Find general solution of non homogenious linear equation

    Homework Statement Find the general solution of the differential equation: y'' + 4y' + 13y' = 169x + 81e^{e-2x} EDIT: Can't get latex to work.. so : http://mathbin.net/60293 The Attempt at a Solution 13Ax + 4A + 13B + 9Ce^{-2x} = 169x+81e^{-2x} http://mathbin.net/60294 Now i have no clue...
  36. H

    Constructing Non-Zero Vectors from a Zero Matrix: A Proof of Linear Dependence

    1) Let A be an n x n matrix. Prove that if Ax= 0 for all n x 1matrices, then A=O. Can you show me the steps of solving this problem? Please!
  37. R

    Quick linear equation question

    So i have (r^4)-16 = 0 r^4 = 16 r = 2 So i only have one root As the general solution i have y = C(sub1) * (e^(2x)) + C(sub2) * (e^(2x)) Is this correct? If not please lead me in the right direction
  38. nukeman

    *Quick Linear equation - Equation of a line - Thanks

    Homework Statement Determine an equation of a line through -3,5 and 1, -3 so... What i got is y - 5 = -2(x-(-3) ) So that turns into y - 5 = -2x + 3 correct? now i am suppose to simplify, and the answer is y = -2x -1 how did they get y = -2x -1 from y - 5...
  39. nukeman

    Linear Equation (supply and demand line)

    Homework Statement Question: For a certain commodity the supply equation is given by: S = 2p + 5 At a price of $1, there is a demand for 19 units of the commodity. If the demand equation is linear and the market price is $3, find the demand equation ? Homework Equations...
  40. nukeman

    How Did the Equation Change to y = x + 30?

    **Quick: Just a SIMPLE question on Linear equation. Homework Statement Ok, 5x + 2(30) = y turns into: 5/3x + 20 = y (that is 5 over 3 x) Now it says something I don't understand. "We now have two equations: y = 5/3x + 20 and y = x + 30 (How did it get y = x + 30?)...
  41. L

    How Do You Solve These Simultaneous Linear Equations for L and X?

    Homework Statement Find value L and X. 0.182(L2+X2)=1602 0.182[(555.56+L)2+X2]=2402
  42. W

    Solution to inhomogenous linear equation

    How do I show the difference of two solutions of an inhomogenous linear equation Lu=g with the same g is a solution of the homogenous equation Lu=0. Your help is much appreciated. thanks a lot.
  43. D

    Basic notation (conditional probability delim in linear equation)

    Hey all. Looking at "Pattern Recognition and Machine Learning" (Bishop, 2006) p28-31, the author appears to be using what would ordinarily be a delimiter for a conditional probability inside a linear function. See the first variable in normpdf as below. This is in the context of defining a...
  44. E

    Methods for Solving Linear Algebraic Equations: Which One Is Best?

    For the system of linear algebraic equations: x − y = 1 2x + 3y = 7 a) find solution by the Cramer’s rule; b) find solution by the method of Gaussian elimination; c) write the first iteration of the Jacobi method with the initial guess x^0=y^0=1. I understand Cramer's Rule, and I think...
  45. S

    Solutions to a linear equation and perfect square

    1) Is there any way to find integer solutions for a linear equation ax+by=c, with a,b,c known and without having an another equation to substitute in the above one. ex : 3x+y=394; Is there any worst case for c being very large. 2)Is there any easy and fastest way to get...
  46. U

    A simple problem on linear equation in two variables

    Homework Statement if a+11b is completely divisible by 13 and a+13b is completely divisible by 11 then find the the smallest possible value of a+b. a and b are positive integers. the answer is 28 Homework Equations a+11b= 13x a+13b= 11y The Attempt at a Solution i have equated...
  47. V

    Finding the Equilibrium Price and Quantity for a Simple Linear Equation?

    Homework Statement P = -50Qd + 80 P = 2Qs + 10 P = Price Qd = Quantity demanded Qs = Quantity supplied Find the equilibrium Price and Quantity. Homework Equations Qd = Qs (equilibrium) The Attempt at a Solution Qd = Qs Q Since they both equal to P -50Q + 80 = 2Q + 10...
  48. S

    The effect of modulus in the graph of a linear equation.

    My problem is not knowing the effects of modulus in parts of an equation ( in this case linear ) on the parts of the graph. An elaboration will be like y = |bx| + c , what's the effect on the graph compared to y = bx + c and likewise : y = bx + |c| and y = bx + c or even y = b|x| + c compared to...
  49. T

    Linear equation solving in matlab

    Homework Statement I have a matrix [11x10] which I want to solve (Ax=b). Matlab comes with an answer, but I would like to know if there is a possibility to give boundary conditions to this problem. like x_i can't be greater than 300 or something. is it possible to restrict the outcome?2. The...
  50. K

    Help me convert this relationship into a linear equation

    Is there anyway I can convert the attached equation into a linear relationship so that 'a' is the gradient of the straight line. 't' and 'h' are both variables. It doesn't matter exactly what the x and y values are. I just need 'a' to be the gradient of the straight line. I tried lots of...
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