# From the differential equation by eliminating the arbitrary constant from the equatio

1. Feb 2, 2013

### manal950

1. The problem statement, all variables and given/known data

From the differential equation by eliminating the arbitrary constant from the equation
(y - b ) ^2 = 4 (X-a )

http://www7.0zz0.com/2013/02/02/21/747681463.png

2. Feb 2, 2013

### Staff: Mentor

Re: From the differential equation by eliminating the arbitrary constant from the equ

What do you want to do?
The first equation is not a differential equation, and can be solved for y (or x) easily (not with the steps shown in the image).

3. Feb 2, 2013

### epenguin

Re: From the differential equation by eliminating the arbitrary constant from the equ

Probably means form the differential equation.

Well, just differentiate through by x.

4. Feb 2, 2013

### manal950

Re: From the differential equation by eliminating the arbitrary constant from the equ

(y- b ) ^2 = 4 (X- a )

2(y-b)dy/dx = 4 (divide by 2 )

(y-b)dy/dx= 2

then what should I do

5. Feb 2, 2013

### Dick

Re: From the differential equation by eliminating the arbitrary constant from the equ

I don't know what you are trying to do. Yes, (y-b)dy/dx=2. So dy/dx=2/(y-b). If that's what you want to do you are done. You now have a differential equation for y without the initial condition constant.

Last edited: Feb 2, 2013
6. Feb 3, 2013

### manal950

Re: From the differential equation by eliminating the arbitrary constant from the equ

yes now

dy/dx=2/(y-b)

but after that what must I do ?

( 2/dy/dx )^2 = 4(X-a )

7. Feb 3, 2013

### Staff: Mentor

Re: From the differential equation by eliminating the arbitrary constant from the equ

Post the full problem statement please.
We have no idea what you want/have to do, as it is your homework and not ours.

8. Feb 3, 2013

### epenguin

Re: From the differential equation by eliminating the arbitrary constant from the equ

You have formed a differential equation by eliminating an arbitrary constant. That seems to be what you were asked but as Dick says, we have had to guess a bit.