Let the random variables $X_{1}$ and $X_{2}$ have the joint pdf $f\left(x_{1}, x_{2}\right)=1 / \pi$, for $\left(x_{1}-1\right)^{2}+\left(x_{2}+2\right)^{2}<1$, zero elsewhere. Find $f_{1}\left(x_{1}\right)$ and $f_{2}\left(x_{2}\right)$. Are $X_{1}$ and $X_{2}$ independent?