#### Answer

$\delta=0.39$

#### Work Step by Step

We see from the graph that in order for $f(x)$ to be within $\epsilon=0.2$ of $L=4$, we must have
$$2.61 \lt x \lt 3.41.$$
Subtracting $c=3$ from all three sides gives
$$-0.39 \lt x-3 \lt 0.41.$$
Note that $$-0.39 \lt x-3 \lt 0.39 \implies -0.39 \lt x-3 \lt 0.41.$$
Hence for $\delta = 0.39$,
$$0 \lt |x-3| \lt \delta \implies 0 \lt |f(x)-4| \lt \epsilon.$$