Sequences and recurrence relations Quiz

1. A sequence has $u_n=n^2-3n$. Find $u_5$.

• A. $10$
• B. $22$
• C. $12$
• D. $16$

2. $x_1=2$ and $x_{n+1}=3x_n-2$. Find $x_3$.

• A. $4$
• B. $8$
• C. $12$
• D. $10$

3. The sequence $1,-1,1,-1,\dots$ is best described as

• A. increasing
• B. periodic with order $2$
• C. decreasing
• D. periodic with order $4$

4. Which sequence is decreasing?

• A. $u_n=n^2$
• B. $u_n=(-1)^n$
• C. $u_n=10-2n$
• D. $u_n=2^n$

5. $u_1=3$ and $u_{n+1}=4-u_n$. Find $u_{50}$.

• A. $3$
• B. $1$
• C. $4$
• D. $7$