R-formula and Trigonometry

special angles

complementary angles

general angels

basic trigo eqns

graphs of Sine, Cosine & Tangent functions

basic identies

eg. sin^2x+cos^2x=1
secx=1/cosx
cosecx=1/sinx
cotx=1/tanx

proving identies

To prove a identity, we usually start with the side that is more complex looking and simplify the other side

addition formulae

eg. sin(A+B)=sinAcosB+cosAsinB

double angle formulae

eg. sin2A=2sinAcosA
cos2A=cos^2A-sin^2A
tan2A=2tanA/1-tan^2A

R-formulae

eg. Acosx+Bsinx=Rcos(x-alpha)
R= ((squareroot)A^2+b^2)
tan(alpha)=B/A

factor formulae

Eg. sinP+sinQ=2sin1/2(P+Q)cos1/2(P-Q)