Compound Angle Identities (Grade 12 NSC Matric Mathematics): Quizzes

Distributive law doesn't apply to trig

$\cos α \cos β + \sin α \sin β$

$\sin α \cos β + \cos α \sin β$

Sign matches the angle operation

$\cos α \cos β - \sin α \sin β$

$45° + 30°$

$\sin 65°$

$-\sin β$

$\cos(65° - 35°)$

$\sin α \cos β - \cos α \sin β$