Answer
a) $1,3,2,-1,-3,-2,1,3,2,-1$
b) See graph
Work Step by Step
a) We calculate the first ten terms of the sequence $a_n=a_{n-1}-a_{n-2}$:
$$\begin{align*}
a_1&=1\\
a_2&=3\\
a_3&=a_2-a_1=3-1=2\\
a_4&=a_3-a_2=2-3=-1\\
a_5&=a_4-a_3=-1-2=-3\\
a_6&=a_5-a_4=-3-(-1)=-2\\
a_7&=a_6-a_5=-2-(-3)=1\\
a_8&=a_7-a_6=1-(-2)=3\\
a_9&=a_8-a_7=3-1=2\\
a_{10}&=a_9-a_8=2-3=-1.
\end{align*}$$
b) Graph the first ten terms:
