A

1003085006

Level: 
A
A sequence \( \left(a_n\right)_{n=1}^{\infty} \) is defined by the recursive formula \( a_1=1\text{, }a_2=2;\ a_{n+2} = \frac12\left(a_{n+1}+a_n\right)\text{, }n\in\mathbb{N} \). What are its first five terms?
\( 1 \), \( 2 \), \( \frac32 \), \( \frac74 \), \( \frac{13}8 \)
\( 1 \), \( 2 \), \( \frac32 \), \( \frac47 \), \( \frac8{13} \)
\( 1 \), \( 2 \), \( 3 \), \( 7 \), \( 13 \)
\( 1 \), \( 2 \), \( \frac23 \), \( \frac47 \), \( \frac{13}8 \)

1003085005

Level: 
A
A sequence \( \left( a_n \right)_{n=1}^{\infty} \) is defined by the recursive formula \( a_1=1;\ a_{n+1}=\frac1{1+a_n}\text{, }n\in\mathbb{N} \). What are its first five terms?
\( 1 \), \( \frac12 \), \( \frac23 \), \( \frac35 \), \( \frac58 \)
\( 1 \), \( \frac12 \), \( \frac23 \), \( \frac34 \), \( \frac58 \)
\( 1 \), \( 2 \), \( \frac32 \), \( \frac53 \), \( \frac85 \)
\( 1 \), \( \frac12 \), \( \frac32 \), \( \frac35 \), \( \frac85 \)

1003085004

Level: 
A
A sequence \( \left(a_n\right)_{n=1}^{\infty} \) is defined by the recursive formula \( a_1=1;\ a_{n+1} = 3a_n\text{, }n\in\mathbb{N} \). What are its first five terms?
\( 1 \), \( 3 \), \( 9 \), \( 27 \), \( 81 \)
\( 3 \), \( 9 \), \( 27 \), \( 81 \), \( 243 \)
\( 1 \), \( 3 \), \( 6 \), \( 12 \), \( 24 \)
\( 1 \), \( 3 \), \( 9 \), \( 30 \), \( 90 \)

1003085003

Level: 
A
We were given the sequence \( \left(\sin\left(n\cdot\frac{\pi}2\right)\right)_{n=1}^{\infty} \). What are the first five terms?
\( 1 \), \( 0 \), \( -1 \), \( 0 \), \( 1 \)
\( 1 \), \( 0 \), \( 1 \), \( 0 \), \( 1 \)
\( -1 \), \( 0 \), \( 1 \), \( 0 \), \( 1 \)
\( 0 \), \( -1 \), \( 0 \), \( 1 \), \( 0 \)