Sudut Negatif

\(\sin (-240^{\circ}) = -\sin 240^{\circ}\)

\(\sin (-240^{\circ}) = -[\sin (180^{\circ} + 60^{\circ})]\)

\(\sin (-240^{\circ}) = -[-\sin 60^{\circ}]\)

\(\sin (-240^{\circ}) = -[-\frac{1}{2}\sqrt{3}]\)

\(\sin (-240^{\circ}) = \frac{1}{2}\sqrt{3}\)

\(\cos (-315^{\circ}) = \cos 315^{\circ}\)

\(\cos (-315^{\circ}) = \cos (360^{\circ}\:-\:45^{\circ})\)

\(\cos (-315^{\circ}) = \cos 45^{\circ}\)

\(\cos (-315^{\circ}) = \frac{1}{2}\sqrt{2}\)

\(\tan (-300^{\circ}) = -\tan 300^{\circ}\)

\(\tan (-300^{\circ}) = -[\tan (360^{\circ}\:-\:60^{\circ})]\)

\(\tan (-300^{\circ}) = -[-\tan 60^{\circ}]\)

\(\tan (-300^{\circ}) = -[-\sqrt{3}]\)

\(\tan (-300^{\circ}) = \sqrt{3}\)