# Thread: y=y+2 Seems Simple, but i can't match the answer up to it.

1. ## y=y+2 Seems Simple, but i can't match the answer up to it.

The equation is:
dy/dx=y+2

Can anyone explain this?

2. ## Re: y=y+2 Seems Simple, but i can't match the answer up to it.

The answer looks correct. You can easily check if it's correct yourself by finding the derivative and plugging it back into the equation.

3. ## Re: y=y+2 Seems Simple, but i can't match the answer up to it.

If you also want to see why write
the equation is seperable and can be written as
$\displaystyle \int \frac{dy}{y+2} = \int dx$

so
$\displaystyle \ln (y+2) = x + c$

then taxing the exp of both sides and writing the arbitrary constant as C = ln c gives the solution as you have it

4. ## Re: y`=y+2 Seems Simple, but i can't match the answer up to it.

Or you can check the answer by taking the derivative of it:

$\displaystyle \frac{d}{dx} y(x) = Ce^x$

So you put this back into the differential equation:

$\displaystyle Ce^x = [Ce^x - 2] + 2$

It turns out to be true.