Formule trigonometrice
sin²t+cos²t=1 ;t=2k¶+t* ;t*€(0,2¶ )
sin t=sin(2k¶+t)
cos t=cos(2k¶+t)
sin(a±b)=sin a cos b± sin b cos a
cos(a+b)=cos a cos b-sin a sin b
cos(a-b)=cos a cos b+sin a sin b
cos(¶/2-t)=sin t
sin(¶/2-t)=cos t
cos (-t)=cos t
sin(-t)= -sin t
cos (¶-x)= -cos x
sin(¶-x)=sin x
sin(¶+x)= -sin x
sin 2x=2sin x cos x
cos 2x=cos² x-sin² x =2cos² x-1=1-2sin² x
sin 3x= 3sin x-4sin³ x
cos 3x=4cos³ x-3cos x
tg (-x)=-tg x x € R-A
tg(¶+x)=tg x x € R-A
ctg(-x)=-ctg x x € R-B
ctg(¶+x)=ctg x x € R-B
