Nilai dari sin 210°-3.cos300°+2tan225°adalah
Sin 210°
= sin (180° + 30°)
= – sin 30°
= -1/2
cos 300°
= cos (360° – 60°)
= cos 60°
= 1/2
Tan 225°
= Tan (180° + 45°)
= Tan 45°
= 1
2 sin 210° – 3. cos 300° + 2. Tan 225°
= 2. (-1/2) – 3. (1/2) + 2. 1
= -1 – 3/2 + 2
= -3/2 + 1
= -3/2 + 2/2
= -1/2