Nilai dari trigonometri A.sin 270 B.cos 240 C.sec 210

A. Sin270 = sin(360-90)
= -sin90
= -1
B. Cos240 = cos(180+60)
= -cos60
= -1/2
C. Sec210 = 1/cos210
= 1/cos(270-60)
= 1/-sin(270-60)
= 1/-sin60
= 1/1√3/2
= 2/√3