This video lecture from Vectors (F.Sc. second year Mathematics) covers: Question 11 of exercise 7.3. In this question we prove the identity cos (α + β)=cos(α).cos(β) - sin(α).sin(β) using vectors. Find more e-learning material and educational video lectures in Urdu at maktab.pk. These videos are free to use for promotional and commercial purpose by keeping the credits to Maktab.
