Hello!

I had to solve a physics problem (related to gases) and I fell over a DE that I don't know how to solve. (I didn't see its type in Chris' tutorial).

I must find $\displaystyle x(t)$ such that $\displaystyle \frac{d^2x}{dt^2}=Gx(t)+K$, where G and K are constants.

I probably made a mistake, because I don't know if we can solve it algebraically and it should describe a harmonic motion.

I appreciate any help in solving it. Thank you.