Question 3: Prove the following identities: Make sure to show your steps with LS/RS: a) [3 marks] 12tan x + tan²x = 1-sin 2x 2 cos x b) [3 marks] (cos x)(cos y) = ½ [cos(x + y) + cos(x − y)] c) [4 marks] COS X 1+sinx + 1+sin x COS X = 2sec x (Source: Ministry of Education (2011). Advanced Functions. Grade 12. University Preparation) /10

Fig: 1