Differential equation Definition and 1000 Threads

Homework Statement dy/dx = 3 - 6x + y - 2xy Homework Equations dy/dx + p(x)y = c p(y) dy = q(x) dx The Attempt at a Solution Just realized where my mistake was, sorry!

Homework Statement Please see attachment Homework Equations Please see attachment The Attempt at a Solution Please see attachment. I am supposed to compare coefficients but it doesn't seem possible. what do I do next? (also, if i have posted this in the wrong forum...I...

I just ran into an interesting problem... which I had wrong :eek: What are the solutions to the following differential equation? $$\frac{dy}{dx} = \sqrt y \qquad \text{with }y(0)=0$$

Homework Statement Homework Statement Solve \frac{dz}{dt} + 3 t e^{t+z} = 0 Homework Equations None that I can think of... The Attempt at a Solution "Rearranging" the given question, we get: \int \frac{dz}{e^z} = -3\int t e^t dt -e^{-z} = -3 \left( t e^t - e^t \right)...

I have the following differential equation \frac{\partial}{\partial t}\left(\frac{a}{X}\right)+\frac{X}{b}\frac{ \partial Y}{\partial t}+\frac{c}{X}=0 where a, b and c are constants and X is a function of t. I want to solve it for Y analytically (if possible) or numerically.

I have the following differential equation \begin{equation} \frac{\partial b}{\partial x}=\frac{b-c}{c^{2}}\end{equation} where b and c are both functions of x. However, although I have a closed form relation between c and x, I do not have such a closed form relation between b and x...

Solve: dx/dt +2y+ex=t2 dy/dt-x+xex=0 Please help for this simultaneous differential equations

Are the equations listed below differential equations? If so, to understand them what level of calculus do I need? I only did alegbra 2 in high school. Δ Wi = η * (D-Y).Ii I(n,EF)=OF(n,EF)*I(n-1,EF) I(1,EF)=OF(1,EF)

Hi

Homework Statement y''+2y'+y=xe-x Homework Equations Yc=c1e-x+c2xe-x relevant info on textbook: "If any term of yp is a solution of the complementary equation, multiply yp by x (or by x2 if necessary)." >> i don't understand the part where it says "a solution of the complementary equation"...

Here is the question: Here is a link to the question: Third order linear differential equation? - Yahoo! Answers I have posted a link there to this topic so the OP can find my response.

Homework Statement solve: y""+6y'+9y=e-3x/x3 Homework Equations y=yc+yp The Attempt at a Solution I found yc=C1e-3x+C2xe-3x and am having difficulties finding yp. I am wondering which method would be the best to determine yp: - annihilators - undetermined coefficients -...

Homework Statement \frac{d^2 y}{dx^2}\cdot\frac{dy}{dx}=x(x+1), \hspace{10pt} y(0)=1, \hspace{5pt} y'(0)=2 Homework Equations None I can think of... The Attempt at a Solution The only thing I even thought to try was turn it into the form: \frac{d^2 y}{dx^2}{dy}=x(x+1){dx}...

Homework Statement x2y"-(x2+2x)y'+(x+2)y=0 known solutions: y1(2)=2 y1'(2)=1 y2(2)=2e2 y2'(2)=3e2 Determine the wronskian Homework Equations yc=C1er1x+C2er2x I also know how to find the wronskian via a determinant The Attempt at a Solution I have tried to divide out...

Homework Statement A 44 gallon barrel of oil develops a leak at the bottom. Let A(t) be the amount of oil in the barrel at a given time t. Suppose that the amount of oil is decreasing at a rate proportional to the product of the time elapsed and the amount of oil present in the barrel. a...

Homework Statement Given y_1(x)=x is a solution to (2x-1)y''-4xy'+4y=0, find y(2) given (y(1),y'(1))=(0, 0). Utilize method of reduction of order. I need help with this as I end up getting some ugly (in my mind, anyways) integrals. Thanks in advance!The Attempt at a Solution Let y=y_1v=xv...

Homework Statement Solve the following differential equation, with the initial-value y(2)=2. y' = \sqrt{ \frac{1-y^{2} } { 1-x^{2} } } Homework Equations The Attempt at a Solution This is a strange ODE. It is continuous when either both |x|<1 and |y|<1 or when both |x|>1 and |y|>1. (Both of...

Homework Statement Find the general solution of: 5y4y' = x2y' + 2xy 2. The attempt at a solution Well I've so far tried to simplify by making the equation really: (5y4-x2)y' - 2xy = 0 Now this will let us use exact equations such as: N(x,y)= 5y4-x2 and M(x,y)= -2xy...

Hi, I have the following vector differential equation (numerator layout derivatives): \frac{\partial e(v)}{\partial v}=\frac{1}{\beta} \frac{\partial w(v)}{\partial v} \Gamma^{-1} where both ##e(v)## and ##w(v)## are scalar functions of the vector ##v##, and where ##\Gamma## is a...

Homework Statement Given that z = √3x/y show that: Homework Equations ∂2z/∂x∂y = ∂2z/∂y∂x The Attempt at a Solution

Homework Statement (3x^2y+2xy+y^3)dx+(x^2+y^2)dy=0

Homework Statement Use parametrisation first, derive the equation including y and p = \frac{dy}{dx} and use the integrating factor method to reduce it to an exact equation. Leave the solution in implicit parametric form. (y')^{3} + y^{2} = xyy'The Attempt at a Solution I'm really lost at...

1. In some chemical reactions, the rate at which the amount of a substance changes with time is proportional to the amount present. For the change of δ-glucono lactone into gluconic acid, for example, dy/dt= -.6y when t is measured in hours. If there are 90 grams of δ-glucono lactone present...

1. The next differential equation I'm working on is this: dy/dx= e8x - 3y Alright, I thought to cancel out the e, we could take the ln of both sides...? ln(dy/dx) = 8x-3y Is this right so far? It doesn't seem like it's right because... well, how can you have an ln(dy/dx)?? Would...

The differential equation I'm working on is: 4(√(xy))dy/dx=1, y(1)=1 (√(xy)dy/dy)2 = (1/4)2 ((xy)dy/dx)*dx = (1/8)*dx (xy)dy = (1/8)dx (y)dy = (1/(8x))dx ...So I think this is right so far. Now I'm going to take the integral of both sides. ∫(y)dy = ∫(1/(8x))dx...

Homework Statement I want to find the maximum value of x given that the differential equation relating x is: x' = 0.7548 - 599.49x^6 -2.4038x^2 - 0.12236x^1.5 Where x = 0 at t = 0. I have to do this with MATLAB using Euler's Method and here is my code: x = 0 a = 0 % initial t value b = 1000...

Homework Statement Which of the following is a correct expression for ∫1t(s-1)y'(s) ds I know the answer is: a) 1/2(t-1)2y(t) b) 1/2(t-1)2y'(t)+ (t-1)(y(t)-y(1)) c) (t-1)(y(t)-y(1)) d) (t-1)y(t)-∫y(s) ds Homework Equations The Attempt at a Solution I know the...

Homework Statement Which fot he following is a solution to the differential equation: t2y" - 2ty' + 2y = 0 a)e-2tt3 b)et c)t d) t4 I have attached an image of the question Homework Equations The Attempt at a Solution I tried answer d first: y = t4 y' = 4t3...

Homework Statement The Initial value problem: y' - (3/t)y = 0 y(1) = -10 Has the solution: I have attached an image of the question Homework Equations The Attempt at a Solution Firstly I found the integrating factor: u(t) = e∫-3/t dt u(t) = -3/t I plugged...

Homework Statement http://edugen.wileyplus.com/edugen/shared/assignment/test/session.quest1886032entrance1_N10020.mml?size=14&rnd=1360201586591 (b) Solve the initial value problem and find the critical value a0 exactly. y = ? a0 = ? (c) Describe the behavior of the solution...

The solution of the problem \left(\nabla^2 + k^2 \right)\psi(\mathbf{r})=f(\mathbf{r}) is, using green function \psi(\mathbf{r})=-\int G(\mathbf{r},\mathbf{r}_1) f(\mathbf{r}) where for the tridimensional case the Green function is...

Homework Statement Solve the integral of differential equation ∫^{t}_{0} y(\tau) d\tau -\acute{y} (t) = t for t≥0 with y(0)=4 The Attempt at a Solution take laplace both sides \frac{Y}{s} - sY + 4 = \frac{1}{s^{2}} Y \frac{1 - s^{2}}{s} =\frac{1}{s^{2}} - 4 Y...

Homework Statement I am asked to find a singular solution of the D.E. dy/dx = (xy+2y-x-2)/(xy-3y+x-3). I am first solving to find the general solution form of the D.E., and so far have it to: [(x+2)/(x-3)]dx = [(y+1)/(y-1)]dy From here, of course, you integrate both sides, but I am...

A hemispherical bowl of radius a has its axis vertical and is full of water. At time t=0 water starts running out of a small hole in the bottom of the bowl so that the depth of water in the bowl at t is x. The rate at which the volume of water is decreasing is proportional to x. Given that the...

Homework Statement From the differential equation by eliminating the arbitrary constant from the equation (y - b ) ^2 = 4 (X-a ) http://www7.0zz0.com/2013/02/02/21/747681463.png

Here is the question: Here is a link to the question: How to obtain the general solution of ye^(2x) dx = (4+e^(2x))dy? - Yahoo! Answers I have posted a link there to this topic so the OP can find my response.

Hi i have the differential equation \frac{d^{2}}{dt^{2}}X(t) +(A+B\frac{sin^{2}(mt)}{mt})X(t) I have tried by hnd to solve this and am getting knowhere does anyone know how to solve it and then plot X against t (where the constants A, B and m will be arbitrarily added), possibly using maple? I...

I quote an unsolved question posted in MHF (November 7th, 2012) by user NumberMunhcer.

Hi everyone, first post. To anyone who has had experience with the background of the Black-Scholes equation used in finance to price options based on underlying assets (wiki here), I have just one simple question to ask regarding a research paper I must write. Is this equation a stochastic...

Homework Statement This is a Riccatti Equation which my answer is very weird after i solved it.. dy/dx+2y^2=(y/x lnx)+2(ln x)^2 where y=ln x is a particular solution Homework Equations The Attempt at a Solution i first let y=ln x+ 1/w and dy/dx=1/x-1/w^2 and substitute y and...

A falling object satisfies the initial value problem: dv/dt = 9.8 - v/5, v(0) = 0 1.Find the time that must elapse for the object to reach 98% of its limiting velocity. answer: t = 19.56, and for completeness, v = -49e-t/5 + 49 2.How far does the object fall in the time found in part a...

Homework Statement mv'=-gm-kv Find the position function using the initial coniditions of t=0 for all Constants Homework Equations Reverse product rule The Attempt at a Solution My attempt is on my white board. Its attached as a picture.

Homework Statement I'm decent with differential equations for RLC circuits, and I KNOW the stationary current will be zero, but I need help to work it out mathematically, because my maths gets me -2.4A (...) L: 0.05H C: 0.04F R: 3 Ω U (source) = 1 V I've got the transient solution: c1e-10t +...

The first part of this problem asks me to solve the following for y' : \left( 1 + {y'}^2 \right)y = k^2 So I have: 1 + {y'}^2 = \frac{k^2}{y} {y'}^2 = \frac{k^2}{y} - 1 y' = \sqrt{{\frac{k^2}{y} - 1}} Then I am asked to show that if I introduce the following: y = k^2 \sin^2t Then...

the problem is (x+x^4)dy+y(y^3-x^3)dx=0 well I know that this is not a separable equation, homogenous equation or an exact equation...so i try to solve it by treating it as a non exact DE by finding out the integrating factor...but the both IF come out in term of x and y which involve 2...

The problem is dx/dt = (x+9)^2. This is separable so I made it dx / (x+9)^2 = dt. The only method I can think of using for something like this is partial fraction, but I can't get it to work with A/(x+9) + B/(x+9). Can anyone find a method that works?

Homework Statement Solve the following differential equation: y*e^(x^2)*dy/dx=x+xy Homework Equations y'+P(x)*y=Q(x) The Attempt at a Solution I tried to modify the equation to match the first order linear one, and I got: e^(x^2)*dy/dx=x/y+x (divided everything by y), but...

Homework Statement Solve the initial value problem: t(dy/dt)+8y=t^3 where t>0 and y(1)=0 Homework Equations None? The Attempt at a Solution It's a linear equation, so rearranged to dy/dt+8y/t=t^2. Took the integrating factor e^(∫8/tdt)=t^8 and multiplied through...

The problem is : dy/dx=(x(x^2+1))/4y^3 when y(0)=-1/√2 This is my work so far: ∫4y^3dy=∫x(x^2+1)dx (y^4)/2=((x^2+1)^2)/2+c The answer from the textbook is y=-(√(x^2+2)/2) As you can see, my work will never equal the textbook answer when you put it in the y= stuff form. What did I do wrong?

Homework Statement y = 2xy' + y(y')2 ; y2 = c1(x + c1/4) Homework Equations So far I've gotten the second equation to be: y = (c1x + c12/4)1/2 I was then going to take the derivative of that equation and plug them into the first equation after setting it to zero. Is that the...