Sin²a+sin²b+2sinasinb+cos²a+cos²b+2cosacosb=
=(sin²a+cos²a)+(sin²b+cos²b)+2(sinasinb+cosacosb)=
=1+1+2cos(a-b)=2(1+cos(a-b))
4cos²((α-β)/2)=4*(1+cos(a-b))/2=2(1+cos(a-b))
A)(x-3)(x-2)^2=(x-3)(x^2-4x+4)=x^3-4x^2+4x-3x^2+12x-12=x^3-x^2-16x-12
б)(5-a)^2=25-10a+a^2
(b₁*b₁q*b₁q²*b₁q³*b₁q⁴*b₁q⁵*b₁q⁶)/(b₁)⁶=(b₁)⁷*q²¹/(b₁)⁶=b₁*q²¹=b₂₂.
Ответ: А).