# Can't figure out this seperable diffEQ!

1. Feb 8, 2006

### mr_coffee

Can't figure out this seperable diffEQ! :(

Hello everyone 'ive been trying to figure out this easy looking Differential Equation and yet its wrong! weee!
Here is the problem:

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 a function in the form
F(x,y) = G(x) + H(y) =K.

Find such a solution and then give the related functions requested.
F(x,y) = G(x) + H(y) = ?

I submitted:

which was wrong.

here is my work:

Any help would be fantastical. <--yeah i'm pretty sure thats not a word.

2. Feb 8, 2006

### benorin

Go back and insert a pair of parens on the left hand side of the second line that it would read

$$\int e^y(\sin y+9\cos y) dy = \int(14x+5)dx$$

3. Feb 8, 2006

### benorin

Know also that

$$\int e^y(\sin y+9\cos y) dy = e^y(5\sin y+4\cos y)$$

and in closing note that fantastical is now a word by extension, since, for example antideparameterizationism is likwise wise a word, for I am very much opposed to not eliminating a perfectly useful paramter from my solutions (especially once they've been obtained by inserting it cleverly into the givens,) and I am thus a practioner of antideparameterizationalism. :rofl:

Last edited: Feb 8, 2006
4. Feb 8, 2006

### mr_coffee

hah i like your way of thinking.
I submitted

and they told me to f off, i was quite distraught. Any ideas what i did now
?

5. Feb 8, 2006

### benorin

try writing it in the order (fcn. of x) + (fcn. of y), e.g. G(x) + H(y), such as

-7*x^2-5*x + 5*exp(y)*sin(y)+4*exp(y)*cos(y)

6. Feb 8, 2006

### mr_coffee

ur the man!
For some reason, i had to multiply through -1 to make it work, it loved this answer: