WAEC - Mathematics (1992 - No. 32)
The value of sin 210° is
\(-\frac{1}{2}\)
\(-\frac{\sqrt{3}}{2}\)
\(\frac{1}{2}\)
\(\frac{\sqrt{2}}{2}\)
\(\frac{\sqrt{3}}{2}\)
คำอธิบาย
sin 210 = - sin (210 - 180) = - sin 30
= \(-\frac{1}{2}\)
sin 210 = - sin (210 - 180) = - sin 30
= \(-\frac{1}{2}\)