# Easy differential equation question

1. Nov 2, 2008

### rock.freak667

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

Obtain the ordinary differential equations whose solution is
i)y=Ae2x+Bxe2x
ii)y=mx+ h/m where h is a constant and m is to be eliminated

2. Relevant equations

3. The attempt at a solution

For the first one it is simply:
y''-4y'+4y=0

For the second one it is just y''=0?

Last edited: Nov 3, 2008
2. Nov 3, 2008

### gabbagabbahey

Not quite, y''=0 has a general solution y=Ax+B with no restrictions on A or B....you want an ODE that gives a more restrictive solution, one where A=m and B=(a constant)/m...so you need a more restrictive ODE...try a first order ODE instead of a second order one.

3. Nov 3, 2008

### rock.freak667

But if I use a 1st order ODE, I won't eliminate the constant m