Questions tagged [reduction-of-order-ode]
To use when our aim is to solve an ODE (of any order) only with reduction of order method. If you just want to solve an ODE use the tag differential-equations.
60 questions
0 votes
1 answer
82 views
Question about conditions required for an alternate method of solving reducible 2nd order ODEs.
What are the conditions under which the formula I've given below for an inhomogeneous reducible 2nd‐order ODE is valid? I have the second‐order inhomogeneous ODE $$ y''(t) \;+\; h(t)\,y'(t)\;+\;q(t)\,...
3 votes
2 answers
97 views
When solving a third-order ODE using reduction of order, what happens when the v’ term drops out
Given question Given $y=x$ is a solution of $6x^3y’’’ - 24x^2y’’ + 48xy’-48y = 0$. Find the general solution if $x>0$. My work Since we are given that $y = x$ is a solution, my first approach would ...
1 vote
1 answer
64 views
Frobenius method for solving differential equation
Need help solving this differential equation$$xy''+(x+l)y'+ly=0$$ where $l\in \mathbb{R}$\ I tried using the Frobenius method. $x_0=0$ is a regular singular point and Assume that we have the solution ...
0 votes
2 answers
144 views
How can I solve a Bessel equation with Reduction of order?
If $y_{1}(x) = \frac{\sin(x)}{\sqrt(x)}$ is one solution of the differential equation $$x^2y'' +xy' + (x^2-\frac{1}{4})y = 0$$ find the second solution $y_{2}(x)$. My effort using Wronskian The ...
3 votes
1 answer
70 views
Reduction of Order to solve, but can't get right answer
Given the equation y'' + 2y' + y = 0 and the solution y1 = ${xe}^{-x}$. Solve for a second solution $y_2$. I've solved it twice and get $y_2 = {xe}^{-x}(-{x}^{-1}+c)$ , but that's not being counted ...
0 votes
1 answer
86 views
Simple second order equation to be solved by reduction of order
This is the question, given that; $y_1 = x$ $$ (x^2+1)y''-2xy' +2y = 0 $$ other form $$ y''-\dfrac {2x}{(x^2+1)}y' +\dfrac {2}{(x^2+1)}y = 0 $$ using the formula $y_2 = y_1 \int e^{-\int p(x)dx} / y_1^...
2 votes
1 answer
458 views
How to reduce O.D.E. into first order? [closed]
How to reduce the following O.D.E. into first order? $v v_{yyy} + 2 v v_{yy}-v_{y}v_{yy} + v_{y} v^3 + v_y v -v_{y}^2 = 0$, where $v=v(y)$ and $v_{y}$ is the derivative w.r.t. $y$. I tried it by ...
3 votes
2 answers
388 views
Reduction of Order to Solve $y'' =-y^{3}$
I want to solve $y'' +y^3 = 0$ with the boundary conditions $y(0) = a$ and $y(k) = b$. My goal is to reduce this problem to $y' +y^2 = 0$ while solving but I'm not sure it can be done. I tried ...
2 votes
3 answers
305 views
How to reduce the ODE to first order?
How to reduce the following O.D.E. into first order? $$(vv_{xxx}-v_{x}v_{xx})g^2 + v^3 v_x = 0, \tag{1}$$ where $v=v(x)$ and $v_{x}$ is the derivative w.r.t $x$, $g$ is a constant. After integration, ...
0 votes
2 answers
243 views
How to reduce this differential equation into first-order differential equation?
How can we reduce this differential equation into first-order differential equation? $\left( {\frac {\rm d}{{\rm d}z}}U \left( z \right) \right) ^{3}{ \frac {{\rm d}^{2}}{{\rm d}{z}^{2}}}U \left( z \...
0 votes
1 answer
219 views
Reduction of Order for two 2nd Order ODEs to a system of four 1st order ODE with Initial Conditions and sine functions
I am trying to determine how to turn these two 2nd order ODEs into a system of four 1st order ODEs with initial conditions. Afterwards, I am to turn it into a matrix. eqn 1: $$3.2\theta''_1 + 1.44[\...
0 votes
0 answers
57 views
Error Reduction of System of OverDetermined Algebraic Equations
I am trying to perform model reduction on a system of algebraic equations by reducing the number of variables in the system. In doing so I am not trying to remove equations from the system, rather I ...
1 vote
1 answer
53 views
Solving a linear ODE of second order by reducing the order
Solve the equation $ty''-y'+4t^3y=0, t>0$ given that $\sin(t^2)$ is a solution. (I am aware that this has been asked before but the answers did not help me). My attempt: I want to use reduction of ...
0 votes
0 answers
48 views
Reducing the order of differential equations
How the following 4th order linear differential equation can be reduced to two 2nd order differential equations, if possible. $a$ and $b$ are constants. $$X^2 Y^{(4)}(X) + 2 (a+2) X Y^{(3)}(X) + (...
2 votes
3 answers
245 views
Solve the ODE $y y''=3(y')^2$ using Reduction of Order
For the reduction of order method, we are supposed to guess a solution, $y_1$, and assume that the second solution (this will be second order as the title shows) is of the form $y_2=uy_1$. But I'm ...