Solution of linear differential equation

Click For Summary
SUMMARY

The discussion focuses on solving the linear differential equation represented by the equation xdy + (xy + y - 1)dx = 0. The transformation into a standard linear form is achieved by rearranging the equation to dy/dx + [(x + 1)/x]y = 1/2. The integrating factor method is then applied, utilizing the integrating factor u = exp[int(P(x))] to facilitate the solution. The participants emphasize the importance of correctly identifying P(x) and Q(x) to proceed with the solution effectively.

PREREQUISITES
  • Understanding of linear differential equations
  • Familiarity with integrating factors in differential equations
  • Knowledge of the method of separation of variables
  • Basic calculus concepts, including integration and differentiation
NEXT STEPS
  • Study the method of integrating factors in depth
  • Learn how to derive and apply the standard form of linear differential equations
  • Explore examples of solving linear differential equations with variable coefficients
  • Practice converting non-linear differential equations into linear forms
USEFUL FOR

Students studying differential equations, mathematics educators, and anyone looking to enhance their problem-solving skills in linear differential equations.

clope023
Messages
990
Reaction score
130

Homework Statement



solve differential equation

xdy + (xy+y-1)dx=0


Homework Equations



dy/dx + P(x)y = Q(x)

u = exp[int(P(x)] - integrating factor

exp[int(P(x))]*[dy/dx+P(x)y = Q(x)]

=> d/dx[P(x)]y = exp[int(P(x))]Q(x)

int[d/dx[P(x)]y = exp[int(P(x))]Q(x)]

solution is with respect to y.

The Attempt at a Solution



xdy = -(xy+y-1)dx

dy/dx = (1-y+xy)/x

dx/dy = x/(1-y+xy)

dx/dy = x-x/y+1/y

dx/dy - x + x/y = 1/y

I'm stuck here, I'm just not sure who to get the equation into a linear form where I could take the integrating factor and solve for x in the case since I switched the dependent variables to see if that wouldn't make it more complicated, any help from that point on would be greatly appreciated.
 
Physics news on Phys.org
divide the whole equation by dx, then u get x(dy/dx)+xy+y-1=0

move the 1 to other side, and factor a y out , and u get

x(dy/dx)+y(x+1)=1

divide by x

(dy/dx)+[(x+1)/x]y=1/2

now u in form ,and u have P(x)Y :)

the rest i think you know how to do it
 

Similar threads

  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 25 ·
Replies
25
Views
2K
Replies
3
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
Replies
3
Views
2K
Replies
4
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K