3)令输入x3(n)=x(m)+x2(n)=6(m)+6(n-1) (-1)=1,求输出y(m) n)=ay(n-1)+x(n),得 )=ay3(-1)+x3(0)=a+1 y=ay(O)+x(1)=a2+a+1 2(2)=ay3(1)+x3(2)=a(2+a+1) y3(3)=ay2(2)+x3(3)=a2(a2+a+1)同步骤1),由 y3(n-1)=-[y(n)-x3(m) y3(m)=an(a2+a+1),n≥1 得y3( n≤ y3(n)=(1+a)6(m)+(1+a+a2)au(n-1) +a”(-n-1)3 1 2 3 3 ( ) ( ) ( ) ( ) ( 1) ( 1) 1 ( ) x n x n x n n n y y n = + = + − − = 3)令输入 , 由 ,求输出 3 3 3 3 3 3 2 3 3 3 2 3 3 3 2 2 3 3 3 1 2 3 ( ) ( 1) ( ) (0) ( 1) (0) 1 (1) (0) (1) 1 (2) (1) (2) ( 1) (3) (2) (3) ( 1) ( ) ( 1) 1 n y n ay n x n y ay x a y ay x a a y ay x a a a y ay x a a a y n a a a n − = − + = − + = + = + = + + = + = + + = + = + + = + + 由 ,得 , 3 3 3 1 3 1 1 ( 1) [ ( ) ( )] ( ) 1 n y n y n x n a y n a n + − = − = − 同步骤 ),由 得 , 2 1 3 ( ) (1 ) ( ) (1 ) ( 1) n y n a n a a a u n − = + + + + − 1 ( 1) n a u n + + − −