is the network of devices with ability to connect and exchange data

Show that the moving average process \( X_{n}=Z_{n}+\beta Z_{n-1} \) is weakly stationa ry, where \( Z_{n} \) is a white noise process with mean \( \mu \) and variance \( \sigma^{2} \). (4 Marks)

Point A has coordinates \( (-13,-9) \) Point B has coordinates \( (1,15) \)

7. If \( a=x^{2}+\frac{x}{3} \) \( z=6 x-2 \) What is a in terms of \( z \) ? A) \( \frac{z^{2}-4 z+8}{36} \) B) \( \frac{z^{2}-4 z+8}{12} \) C) \( \frac{z^{2}-6 z+8}{36} \) D) \( \frac{z^{2}-6 z+8}{12} \)

4.(UEPB) 0 produto dos números complexos \( (3-1) \cdot(x+2 y i) \) é un número real quando o ponto \( P(x, y) \) está sobre a reta de equaçio \( \begin{array}{ll}\text { j) } 6 x+y=0 & \text { d) } 6 y-x=0 \\ \text { b) } 6 x-y=0 & \text { e) } 3 y-x=0 \\ \text { () } x+6 y=0 & \text { - }\end{array} \)

\( 3 \quad t ^ { 2 } ( x - y ) + z ^ { 2 } ( y - x ) \)