Finding Orthogonal Trajectories (differential equations)
Find the set of orthogonal functions on the function
$$frac{x}{y}+frac{y}{x}=C(xy)^2$$ where C is non zero.
What I tried doing was first multiplying both sides with $xy$ to get $x^2+y^2=Cx^3y^3$ and now I derived both sides to get
$$2x+2yy'=3C(x^2y^3+x^3y^2y')$$
and by grouping the parts with $y'$ we get
$$y'(3Cx^3y^2-2y)=2x-3Cx^2y^3$$
here I try to eliminate C by putting $C=frac{x^2+y^2}{x^3y^3}$ and i get
$$y'(frac{3(x^2+y^2)x^3y^2}{x^3y^3}-2y)=2x-frac{3(x^2+y^2)x^2y^3}{x^3y^3}$$
canceling out i get
$$y'(frac{3(x^2+y^2)}{y}-2y)=2x-frac{3(x^2+y^2)}{x}$$ Multiplying by $xy$ i get
$$y'(3(x^2+y^2)x-2y^2x)=2x^2y-3(x^2+y^2)y$$
Now I know I have to replace $y'=frac{dy}{dx}$with $-frac{dx}{dy}$
So now I have
$$frac{-dx}{dy}(3(x^2+y^2)x-2y^2x)=2x^2y-3(x^2+y^2)y$$
and i'm not sure how to go on from here.
I would really appreciate if somebody could help me from here on out. Or show me an alternate way of doing this
differential
add a comment |
Find the set of orthogonal functions on the function
$$frac{x}{y}+frac{y}{x}=C(xy)^2$$ where C is non zero.
What I tried doing was first multiplying both sides with $xy$ to get $x^2+y^2=Cx^3y^3$ and now I derived both sides to get
$$2x+2yy'=3C(x^2y^3+x^3y^2y')$$
and by grouping the parts with $y'$ we get
$$y'(3Cx^3y^2-2y)=2x-3Cx^2y^3$$
here I try to eliminate C by putting $C=frac{x^2+y^2}{x^3y^3}$ and i get
$$y'(frac{3(x^2+y^2)x^3y^2}{x^3y^3}-2y)=2x-frac{3(x^2+y^2)x^2y^3}{x^3y^3}$$
canceling out i get
$$y'(frac{3(x^2+y^2)}{y}-2y)=2x-frac{3(x^2+y^2)}{x}$$ Multiplying by $xy$ i get
$$y'(3(x^2+y^2)x-2y^2x)=2x^2y-3(x^2+y^2)y$$
Now I know I have to replace $y'=frac{dy}{dx}$with $-frac{dx}{dy}$
So now I have
$$frac{-dx}{dy}(3(x^2+y^2)x-2y^2x)=2x^2y-3(x^2+y^2)y$$
and i'm not sure how to go on from here.
I would really appreciate if somebody could help me from here on out. Or show me an alternate way of doing this
differential
1
This seems like a homogeneous equation . Try substituting $$x=vy$$ .
– Chinmaya mishra
Nov 20 '18 at 14:14
Thanks. Completrly forgot to check that. . .
– westlife
Nov 20 '18 at 14:19
add a comment |
Find the set of orthogonal functions on the function
$$frac{x}{y}+frac{y}{x}=C(xy)^2$$ where C is non zero.
What I tried doing was first multiplying both sides with $xy$ to get $x^2+y^2=Cx^3y^3$ and now I derived both sides to get
$$2x+2yy'=3C(x^2y^3+x^3y^2y')$$
and by grouping the parts with $y'$ we get
$$y'(3Cx^3y^2-2y)=2x-3Cx^2y^3$$
here I try to eliminate C by putting $C=frac{x^2+y^2}{x^3y^3}$ and i get
$$y'(frac{3(x^2+y^2)x^3y^2}{x^3y^3}-2y)=2x-frac{3(x^2+y^2)x^2y^3}{x^3y^3}$$
canceling out i get
$$y'(frac{3(x^2+y^2)}{y}-2y)=2x-frac{3(x^2+y^2)}{x}$$ Multiplying by $xy$ i get
$$y'(3(x^2+y^2)x-2y^2x)=2x^2y-3(x^2+y^2)y$$
Now I know I have to replace $y'=frac{dy}{dx}$with $-frac{dx}{dy}$
So now I have
$$frac{-dx}{dy}(3(x^2+y^2)x-2y^2x)=2x^2y-3(x^2+y^2)y$$
and i'm not sure how to go on from here.
I would really appreciate if somebody could help me from here on out. Or show me an alternate way of doing this
differential
Find the set of orthogonal functions on the function
$$frac{x}{y}+frac{y}{x}=C(xy)^2$$ where C is non zero.
What I tried doing was first multiplying both sides with $xy$ to get $x^2+y^2=Cx^3y^3$ and now I derived both sides to get
$$2x+2yy'=3C(x^2y^3+x^3y^2y')$$
and by grouping the parts with $y'$ we get
$$y'(3Cx^3y^2-2y)=2x-3Cx^2y^3$$
here I try to eliminate C by putting $C=frac{x^2+y^2}{x^3y^3}$ and i get
$$y'(frac{3(x^2+y^2)x^3y^2}{x^3y^3}-2y)=2x-frac{3(x^2+y^2)x^2y^3}{x^3y^3}$$
canceling out i get
$$y'(frac{3(x^2+y^2)}{y}-2y)=2x-frac{3(x^2+y^2)}{x}$$ Multiplying by $xy$ i get
$$y'(3(x^2+y^2)x-2y^2x)=2x^2y-3(x^2+y^2)y$$
Now I know I have to replace $y'=frac{dy}{dx}$with $-frac{dx}{dy}$
So now I have
$$frac{-dx}{dy}(3(x^2+y^2)x-2y^2x)=2x^2y-3(x^2+y^2)y$$
and i'm not sure how to go on from here.
I would really appreciate if somebody could help me from here on out. Or show me an alternate way of doing this
differential
differential
asked Nov 20 '18 at 13:53
westlife
868
868
1
This seems like a homogeneous equation . Try substituting $$x=vy$$ .
– Chinmaya mishra
Nov 20 '18 at 14:14
Thanks. Completrly forgot to check that. . .
– westlife
Nov 20 '18 at 14:19
add a comment |
1
This seems like a homogeneous equation . Try substituting $$x=vy$$ .
– Chinmaya mishra
Nov 20 '18 at 14:14
Thanks. Completrly forgot to check that. . .
– westlife
Nov 20 '18 at 14:19
1
1
This seems like a homogeneous equation . Try substituting $$x=vy$$ .
– Chinmaya mishra
Nov 20 '18 at 14:14
This seems like a homogeneous equation . Try substituting $$x=vy$$ .
– Chinmaya mishra
Nov 20 '18 at 14:14
Thanks. Completrly forgot to check that. . .
– westlife
Nov 20 '18 at 14:19
Thanks. Completrly forgot to check that. . .
– westlife
Nov 20 '18 at 14:19
add a comment |
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This seems like a homogeneous equation . Try substituting $$x=vy$$ .
– Chinmaya mishra
Nov 20 '18 at 14:14
Thanks. Completrly forgot to check that. . .
– westlife
Nov 20 '18 at 14:19