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.

you cant chain rule (1/3)(x^1/8)^3 because its only x^1/8 inside the bracket