Precalculus (6th Edition)

$\color{blue}{\approx 1.3 \text{ radians} \\\approx 5 \text{ radians}}$
To approximate the angle whose cosine value is $0.3$, look up in the given figure the angle/s directly above and directly below $x=0.7$ These angles are approximately $1.3$ radians and $5$ radians Thus, the angles are approximately: $\color{blue}{1.3 \text{ radians} \\5 \text{ radians}}$