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

Join the discussion
Registration is free. Start your own thread to ask a follow-up.
2 replies · 2K views
mamma_mia66
Messages
51
Reaction score
0

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.
 
Physics news on Phys.org
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!