(A) For independent events:
\[ P(A \cap B) = P(A) \cdot P(B) = 0.5 \cdot 0.4 = 0.2. \](B) Using the formula:
\[ P(A \cup B) = P(A) + P(B) - P(A \cap B). \]Substituting values:
\[ P(A \cup B) = 0.5 + 0.4 - 0.2 = 0.7. \]Find the values of \( x, y, z \) if the matrix \( A \) satisfies the equation \( A^T A = I \), where
\[ A = \begin{bmatrix} 0 & 2y & z \\ x & y & -z \\ x & -y & z \end{bmatrix} \]
(b) Order of the differential equation: $ 5x^3 \frac{d^3y}{dx^3} - 3\left(\frac{dy}{dx}\right)^2 + \left(\frac{d^2y}{dx^2}\right)^4 + y = 0 $