Solving the Homogeneous Equation y2dx -x(2x+3y)dy =0

In summary, the given equation is a homogenous one and the substitution of x=uy leads to the equation y2udy+y3du - 2x2dy + 3yxdy=0. Dividing this by x^2 yields a simpler form for solving the equation.
  • #1
mamma_mia66
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Homework Statement


y2dx -x(2x+3y)dy =0 I have to recognize the equation and solve it


Homework Equations





The Attempt at a Solution



I did y2dx - (2x2+ 3yx) dy=0
which is a homogeneous now
after I substitude x=uy
dx=udy + ydu

I stuck here after the substitution

y2udy+y3du - 2x2dy + 3yxdy=0

please someone help if I am not in right direction from the begining.
 
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  • #2
mamma_mia66 said:

Homework Statement


y2dx -x(2x+3y)dy =0 I have to recognize the equation and solve it


Homework Equations





The Attempt at a Solution



I did y2dx - (2x2+ 3yx) dy=0
which is a homogeneous now
after I substitude x=uy
dx=udy + ydu

I stuck here after the substitution

y2udy+y3du - 2x2dy + 3yxdy=0

please someone help if I am not in right direction from the begining.
I am more accustomed to write y= ux but your method is equivalent.
Saying x= uy is the same as saying u= y/x. Divide your last equation by [itex]x^2[/itex] and see what you get!
 
  • #3
ok, thanks.
 

FAQ: Solving the Homogeneous Equation y2dx -x(2x+3y)dy =0

What is a homogeneous equation?

A homogeneous equation is a type of differential equation in which all terms have the same degree. This means that all terms are raised to the same power, making the equation easier to solve.

How do you solve a homogeneous equation?

To solve a homogeneous equation, you can use the substitution method. This involves substituting y = vx into the equation, where v is a new variable, and then solving for x in terms of v. Once you have a solution for x, you can substitute it back into the original equation and solve for y.

What is the degree of a homogeneous equation?

The degree of a homogeneous equation is the highest power to which any variable is raised. For example, the degree of y2dx -x(2x+3y)dy =0 is 2, since both y and x are raised to the power of 2.

Can a homogeneous equation have non-constant coefficients?

Yes, a homogeneous equation can have non-constant coefficients. In fact, most homogeneous equations have non-constant coefficients, making it necessary to use the substitution method to solve them.

What is the significance of solving a homogeneous equation?

Solving a homogeneous equation allows us to find a general solution that can be used to solve a variety of problems in different fields of science and engineering. It is also a useful tool in understanding the behavior of systems that exhibit symmetry, as homogeneous equations often describe these types of systems.

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