Tentukan nilai dari:a.cos 330° dan b.sin 120°

Cos (330) = cos (360-30)
cos (330) = cos 30
cos 30 = √3/2

sin 120 = sin (180-60)
= sin 60
= √3/2

Cos 330= cos (360-30)=
=cos 30
=1/2√3
sin 120 = sin ( 180-60)
=sin 60
=1/2√3