hitunglah nilai dari : A) sin 345 B) cos 330 C) tan (-45) D) cos (-60)

[tex]1. \sin(345) \\ =\sin(135 + 210) = \sin(135) . \cos(210) - \cos(135) . \sin(210) \\ = ( \frac{1}{2} \sqrt{2} \times - \frac{1}{2} \sqrt{3} ) - ( - \frac{1}{2} \sqrt{2} \times - \frac{1}{2} \\ = - \frac{1}{4} \sqrt{6} - \frac{1}{4} \sqrt{2} [/tex]

2. cos 330
=cos(360-30)
=cos30
=½√3

3.Tan(-45)=-1

4.cos(-60)=½