Khan Academy Static

Learn about the trigonometric angle addition identities, which help us discuss the trig values of sums of angles in terms of the trig values of the individual angles. For example, we can express sin(x+y) in terms of sin(x), sin(y), cos(x), and cos(y).

4793_Proof_of_the_sine_angle_addition_identity.html

4794_Proof_of_the_cosine_angle_addition_identity.html

4791_Using_the_cosine_angle_addition_identity.html

4792_Using_the_cosine_double_angle_identity.html

4790_Review_of_trig_angle_addition_identities.html