A-Level CAIE Mathematics AS 2.3.2—Trig identities Question Bank

• use trigonometrical identities for the simplification and exact evaluation of expressions, and in the course of solving equations, and select an identity or identities appropriate to the context, showing familiarity in particular with the use of - sect an122 /ii + and cosecc ot122 /ii + - the expansions of sin(A ± B), cos(A ± B) and tan(A ± B) - the formulae for sin 2A, cos 2A and tan 2A - the expression of sinc osab ii+ in the forms sinR !ia^h and cosR !ia^h. e.g. simplifying coss inxx 30 3 60cc- - -^^ hh. e.g. solving tanc ot 4ii+ =, sect an25 2 ii- =, coss in32 1ii+ =.