Question

sin ( 2x + 225 grade ) + sin ( 2x - 45 grade )

Answer 1

observi ca 225=180+45
formula sin(a+b)=sinacosb+sinbcosa
sin(a-b)=sinacosb-sinbcosa

sin(2x)cos(180+45)+sin(180+45)cos(2x)+sin(2x)cos(45)-sin(45)cos(2x)=
poti dezvolta sin(180+45) etc si inlocui etc