Ecli zadanie F(x)=cos²3x-sin²3x=cos(2.3x)=cos6x, to
F´(x)=-6sinx
(cos 2α=cos²α-sin²α)
Ecli F(x)=cosˇ(23)x - sinˇ(23)x, to
F´(x)=(23cosˇ22x)(-sinx)-(23sinˇ22 x)(cosx)=-23(cosˇ22x.sinx+sinˇ22x.cosx)
Ecli F(x)=cos(23x)-sin(23x), to
F´(x)=-23sin(23x)-23cos(23x)=-23(sin(23x)+cos(23x))
Zadanie net točnoe.....