Finding F(x)=G(x)+H(y)=K

  • Thread starter hardatwork
  • Start date
In summary, the conversation discusses a differential equation with an implicit general solution and the process of finding the related functions. The mistake in the solution process is identified and corrected. The final solution is given as G(x)=x+25x3 and H(y)=8/9y9/8.
  • #1
hardatwork
9
0

Homework Statement


The differential equation dy/dx= 35/(y1/8+25x2y1/8 has an implicit general solution of the form F(x,y)=K. In fact, because the differential equation is separable, we can define the solution curve implicitly by the form F(x)=G(x)+H(y)=K.
Find such solution and then give the related functions requested.


Homework Equations





The Attempt at a Solution


dy/dx=35/(y1/8(1+25x2)
1+25x2/35 dx=y1/8dy
1/35[tex]\int1+25x^2 dx[/tex]=[tex]\int y^(1/8) dy[/tex]
x+25x3/105=8/9y9/8
105(8/9y9/8)-x-253=K
so G(x)=x+25x3 and H(y)=8/9y9/8
 
Physics news on Phys.org
  • #2
The problem is that this is incorrect and I don't know what I did wrong. Can someone see my mistake. Thank You in advance
 
  • #3
dy/dx=35/(y1/8(1+25x2)
1+25x2/35 dx=y1/8dy
The bolded line is where you went wrong. Look carefully at what you did. It may be easier to see if you wrote it out "properly:"

[tex]\frac{dy}{dx} = \frac{35}{y^{1/8} + y^{1/8}25x^2}[/tex]

[tex]\frac{dy}{dx} = \frac{35}{y^{1/8}(1 + 25x^2)}[/tex]

Edit: I'm assuming the bolded line really reads ((1+25x2)/35)dx=y1/8dy
 
Last edited by a moderator:
  • #4
So when I separate the variables it should be
y1/8dy=[tex]35/1+25x^2 dx[/tex]
 
  • #5
Assuming you mean y1/8dy=(35/(1+25x2))dx, then yes, that is correct. It is more easily read as (35dx)/(1+25x2) or 35dx/(1+25x2) though, imo.
 
  • #6
Okay. Thank You
 

1. What is the purpose of finding F(x)=G(x)+H(y)=K?

The purpose of finding F(x)=G(x)+H(y)=K is to solve for the unknown variable x and to determine the relationship between the given functions G(x), H(y), and the constant K. This can help in understanding the behavior and properties of the given functions.

2. How do I find the value of x in F(x)=G(x)+H(y)=K?

To find the value of x, you will need to isolate it on one side of the equation. This can be done by subtracting H(y) from both sides and then dividing by the coefficient of x. You can then use substitution to find the value of x by plugging it into the equation.

3. Can I use any values for y when solving F(x)=G(x)+H(y)=K?

Yes, you can use any values for y when solving for F(x)=G(x)+H(y)=K. However, it is recommended to choose values that are easy to work with, such as 0, 1, or -1, to make the calculations simpler.

4. What if there are multiple variables in F(x)=G(x)+H(y)=K?

If there are multiple variables in F(x)=G(x)+H(y)=K, you will need to use substitution to solve for each variable. Choose one variable and solve for it using the given values, then substitute the solved variable into the equation and solve for the remaining variable.

5. Is it possible for F(x)=G(x)+H(y)=K to have no solution?

Yes, it is possible for F(x)=G(x)+H(y)=K to have no solution. This can happen if the given functions G(x) and H(y) do not intersect at any point, or if the given values for x and y do not satisfy the equation. In this case, the equation is said to be inconsistent and has no solution.

Similar threads

  • Calculus and Beyond Homework Help
Replies
2
Views
496
  • Calculus and Beyond Homework Help
Replies
4
Views
802
  • Calculus and Beyond Homework Help
Replies
3
Views
600
  • Calculus and Beyond Homework Help
Replies
6
Views
746
  • Calculus and Beyond Homework Help
Replies
16
Views
1K
  • Calculus and Beyond Homework Help
Replies
2
Views
530
  • Calculus and Beyond Homework Help
Replies
4
Views
85
  • Calculus and Beyond Homework Help
Replies
2
Views
364
  • Calculus and Beyond Homework Help
Replies
20
Views
442
  • Calculus and Beyond Homework Help
Replies
2
Views
718
Back
Top