In Problems 1-10, use a substitution y=xr to find the general solution to the given equation for x>0.

x2y"+2xy'-3y=0

Short Answer

Expert verified

The general solution for the given equation is y=c1x-1/2+√13/2 +c2x-1/2-√13/2 .

Step by step solution

01

Define Cauchy-Euler equations:

In mathematics, a Cauchy problem is one in which the solution to a partial differential equation must satisfy specific constraints specified on a hypersurface in the domain.

An initial value problem or a boundary value problem is both examples of Cauchy problems.

The equation will be in the form of ax2y"+bxy'+cy=0.

02

Find the general solution:

The given equation is,

x2y"+2xy'-3y=0

Let L be the differential operator defined by the left-hand side of equation, that is

L[y](x)=x2y"+2xy'-3y

Let's see,

w(r,x)=xr

Substituting the w(r,x) in place of y(x), you get

L[y](x)=x2(xr )"+2x(xr)'-3(xr)

=x2 (r(r-1)) xr-2+2x (r) xr-1-3 (xr)

=(r2-r) xr+2rxr-3xr

=(r2+r-3) xr

Solving the indicial equation

r2+r-3=0

r= [-1±√(1+12)]/2

r= -1/2±√13/2

There are two distinct roots,

r1= -1/2+√13/2 and r2= -1/2-√13/2

Thus there are two linearly independent solutions given by,

y1=c1x-1/2+√13/2 and y2=c2x-1/2-√13/2

Hence, the general solution for the given equation will be,

y=c1x-1/2+√13/2 +c2x-1/2-√13/2

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Question: In Problems 29–34, determine the Taylor series about the point X0for the given functions and values of X0.

33. f (X)= x3+3x-4, x0= 1

In problems 1-6, determine the convergence set of the given power series.

n=13n3(x-2)n

Show that \(y = {x^{1/2}}w\left( {\frac{2}{3}\alpha {x^{3/2}}} \right)\)is a solution of the given form of Airy’s differential equation whenever w is a solution ofthe indicated Bessel’s equation. (Hint: After differentiating, substituting, and simplifying, then let \(t = \frac{2}{3}\alpha {x^{3/2}}\))

(a)\(y'' + {\alpha ^2}xy = 0,x > 0;{t^2}w'' + tw' + \left( {{t^2} - \frac{1}{9}w} \right) = 0,t > 0\)

(b)\(y'' - {\alpha ^2}xy = 0,x > 0;{t^2}w'' + tw' - \left( {{t^2} - \frac{1}{9}w} \right) = 0,t > 0\)

Question: In Problems 1–10, determine all the singular points of the given differential equation.

6 (x2 - 1)y" + (1 - x)y' + (x2 - 2x + 1)y = 0

For Duffing's equation given in Problem 13, the behaviour of the solutions changes as rchanges sign. Whenr>0, the restoring forceky+ry3becomes stronger than for the linear spring(r=0). Such a spring is called hard. Whenr<0, the restoring force becomes weaker than the linear spring and the spring is called soft. Pendulums act like soft springs.

(a) Redo Problem 13 withr=-1. Notice that for the initial conditions,y(0)=0,y'(0)=1 the soft and hard springs appear to respond in the same way forsmall.

(b) Keepingk=A=1and,ω=10 change the initial conditions toy(0)=1andy'(0)=0. Now redo Problem 13 withr=±1.

(c) Based on the results of part (b), is there a difference between the behavior of soft and hard springs forsmall? Describe.

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free