$$X[k_1, k_2] = \begin{bmatrix} 10 & -2 \ -2 & -2 \end{bmatrix}$$
2.1 (a) The even part of the signal $x[n] = \cos(0.5\pi n)$ is $x_e[n] = \cos(0.5\pi n)$. $$X[k_1, k_2] = \begin{bmatrix} 10 & -2 \
5.1 The FIR filter with a length of 3 and coefficients $b_0 = 1, b_1 = 2, b_2 = 3$ has a transfer function: b_1 = 2