Diff. Eq.

I'm at a loss about how to solve the following differential equation:

x'' = x^0.25

That is, double derivative of x equals x to the 0.25th power.

It's very frustrating because I have a feeling it's very trivial. Can anybody help, please? Thanks.

OK, that worked.  What I did was use the BBCode tags to make it all pretty-like.  Replace all curly brackets "{" and "}" in the following with straight brackets "[" and "]" to achieve the same result:

{code}⌠{/code}{sup}4{/sup}{code}
│x²dx = ?
⌡{/code}{sub}1{/sub}