Trigonometric Modelling - Trigonometry and Modelling (Year 2) - Edexcel A Level Maths

Edexcel A Level Maths. Proof by Contradiction. Year 2, Chapter 1: Algebraic Methods. Addition Formula. Simplifying a cosx + b sinx. Trigonometric Equations.

Timestamps:
00:00 Simplifying a cosx + b sinx
00:22 Exam Q 1
16:11 Exam Q 2
23:11 Exam Q 3
34:05 Exam Q 4

[eesheetashukla]

to get the secnond primciple value do you not do 180- the first principle value you get?? e.g 180 - ( -0.928) rather than finding at 2pi? in the first q

[dfszf]

why is it somertimes 1 and sometimes -1?? even tho its both cos