Trigonometric ratios of allied angles
Trigonometric ratios and identities · Mathematics
Study notes
Q: Express in terms of θ: (a) sin 150° (b) cos 240°. (a) 150° = 180° - 30°: sin 150° = sin 30° = 1/2. (b) 240° = 180° + 60°: cos 240° = -cos 60° = -1/2.