cos²α
Пошаговое объяснение:
sin(α-π/2)=sin(-(π/2-α))=-sin(π/2-α)=-cosα
cos(α-2π)=cosα
tg(3π/2-α)=sin(3π/2-α)/cos(3π/2-α)=-cosα/-sinα=cosα/sinα
sin(π-α)=sinα
cos(4π+α)=cosα
-cosα·cosα+2cosα·sinα·cosα/sinα=-cos²α+2cos²α=cos²α
