# Math Help - differential equation

1. ## differential equation

hey so i had a separable equation:

dy/dx = e^(x-y) + e^x + e^-y + 1

so far i got
dy/dx = e^x / e^y + e^x + e^-y + 1
dy/dx = (e^y + e^x*e^y + 1 + e^x) / e^x

i dont know how to separate the y from the x. any ideas

thanks alot

2. ## Re: differential equation

Originally Posted by ubhutto
hey so i had a separable equation:

dy/dx = e^(x-y) + e^x + e^-y + 1

so far i got
dy/dx = e^x / e^y + e^x + e^-y + 1
dy/dx = (e^y + e^x*e^y + 1 + e^x) / e^x

i dont know how to separate the y from the x. any ideas

thanks alot
Who told you this was separable? Unless I'm missing a cute substitution trick it isn't.

-Dan

3. ## Re: differential equation

(e^y)dy/dx = e^x + e^(x+y) +1 + e^y
(e^y)dy/dx = (e^y + 1)(e^x +1) is separable

4. ## Re: differential equation

Originally Posted by JJacquelin
(e^y)dy/dx = e^x + e^(x+y) +1 + e^y
(e^y)dy/dx = (e^y + 1)(e^x +1) is separable