Angle Sum Identities (1 Viewer)

[sheroom]

Hi everyone (again - sorry...)

From your past experience, is it necessary to learn/memorize how to prove the angle sum identities for trigonometry? I'm referring to the sin(x+y) and so on...

It's easy to prove the double angle identities using the angle sum identities, so I can remember them anyway, but I'm not sure about these ones.

 

[InteGrand]

Hi everyone (again - sorry...)

From your past experience, is it necessary to learn/memorize how to prove the angle sum identities for trigonometry? I'm referring to the sin(x+y) and so on...

It's easy to prove the double angle identities using the angle sum identities, so I can remember them anyway, but I'm not sure about these ones.

I have never seen them asking you to derive these in the exams. It is highly unlikely they would ask you to derive them. The derivation of them is in the syllabus document in Section 5.7 of Page 40: http://www.boardofstudies.nsw.edu.au/syllabus_hsc/pdf_doc/maths23u_syl.pdf