Nilai sin 120° – cos 210° per cos 120° – tan 135°
=
–2√3
Penyelesaian:
sin 120° – cos 210°
cos 120° – tan 135°
= sin (180° – 60°) + cos (180° + 30°)
– cos (180° – 60°) + tan (180° – 45°)
= sin 60° + cos 30°
– cos 60° + tan 45°
= ½√3 + ½√3
– ½ + 1
= √3
-½
= – 2√3