Answer
$$f(x)=\left\{\begin{array}{ll}
-x & -1\leq x\leq0 \\
0.5 x & 0 \leq x\leq2
\end{array}\right.$$
Work Step by Step
As depicted in the graph, the left-hand side of the graph represents a line with a slope of $-1$ and $y$-intercept of $0$. This corresponds to the line of $y=-x$.
We can also conclude from the right side of the graph that it represents a line with a slope of $\dfrac{1}{2}=0.5 $ and $y$-intercept of $0$. This corresponds to the line of $y=0.5x$.
Therefore, the definition for this function can be expressed as:
$$f(x)=\left\{\begin{array}{ll}
-x & -1\leq x\leq0 \\
0.5 x & 0 \leq x\leq2
\end{array}\right.$$