Zgjidhja e ushtrimit 2

Gjeni periodën e vargjeve periodike.

1. $u_n$ = 4(-1)$^n$ + 2(-1)$^n$⁺¹
2. $u_n$ = 2sin(90$n$)$\degree$ + 3cos(90$n$)$\degree$
3. $u_{n+1}$ = $\frac{3}{2}$ - $\frac{9}{4u_n}$ ; $u_1$ = $\frac{1}{2}$
4. $u_{n+1}$ = 4$(\frac{u_n-2}{u_n})$ ; $u_1$ = 3