## Trigonometry (10th Edition)

$\sin(-x)=-\sin(x)$
1. Set up calculator in degrees $\sin 10^{\circ}\approx0.1736$ $\sin (-10)^{\circ}\approx0.1736$ 2. Pick up more examples $\sin30^{\circ}=0.5$ $sin (-30)^{\circ}=-0.5$ $\sin90^{\circ}=1$ $sin (-90)^{\circ}=-1$