(a)(30%) Given
$$
\Xi = \begin{bmatrix}
\sigma_1^2 & \rho \sigma_1 \sigma_2 \\
\rho \sigma_1 \sigma_2 & \sigma_2^2
\end{bmatrix}
$$
Find $|\Xi|$, which is notation for determinant of $\Xi$ and $\Xi^{-1}$, inverse matrix of $\Xi$
Note that with these results you can easily show Equation 5.11
Text
$$
P(x_1,x_2) = \frac{1}{2 \pi \sigma_1 \sigma_2 \sqrt{1-\rho^2}} \exp \left[ -\frac{1}{2(1-\rho^2)} (z_1^2 - 2 \rho z_1 z_2 + z_2^2) \right]
$$