Question

PAKAI CARA YG JELAS DAN LENGKAP
1. nilai dari (sin 60°+ cos 120°) ( cos 330° - sin 210°)
2. nilai dari tan 60°-2sin330° +2cos 150°
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Answer 1

1. (sin 60°+ cos 120°) ( cos 330° - sin 210°)

= (sin 60°+ cos (180-60)°) ( cos (360-30)° - sin (180+30)°)

=(sin 60°+ (-cos 60°)) ( cos 30° - (-sin30°))

=((1/2 √3) + (-1/2))((1/2 √3) - (-1/2))

=((1/2 √3)² - (-1/2)²)

=((3/4)-(1/4))

=-2/4

=-1/2

2. tan60°-2sin330° +2cos 150°

= tan60°-2sin(360-30)° +2cos (180-30)°

=tan60°-2(-sin30°) +2(-cos30)°

=tan60°+2sin30° -2cos30°

=(√3)+2(1/2)-2(1/2 √3)

=(√3)+1-(√3)

=1