**Assume that two random variables (X,Y) are uniformly distributed on a circle with radius a. Then the joint probability density function is**

\(f(x,y) = \frac{1}{\pi a^2}, x^2 + y^2 <= a^2\),

\(f(x,y) = 0, otherwise\)

Find the expected value of X.

\(f(x,y) = \frac{1}{\pi a^2}, x^2 + y^2 <= a^2\),

\(f(x,y) = 0, otherwise\)

Find the expected value of X.

E(X) = \(\int^{\infty}_{- \infty}\int^{\infty}_{- \infty}\frac{x}{\pi a^2} dxdy\)

Is this correct so far? What are the limits of the integral supposed to be?