Let $ \xi $ $ \sim \operatorname{Uniform}[0, 1]$ ( continuous).
I need to find the meaning of an expression $ \mathbb{E}(\xi | \xi^2) $.
When we calc $ \mathbb{E}(\xi^2 | \xi) = \xi^2$ because $\xi^2$ sigma measurable $\xi$.
But how to calc in my case?