Решите пожалуйста №8.081
sin^2(π/5)*cos^2(π/5)=((1/2)*(2sin(π/5)*cos(π/5)))^2= =(1/4)sin^2(2π/5) 1-cos^4(2π/5)-cos^2(2π/5)*sin^2(2π/5)= 1-cos^2(2π/5)*(cos^2(2π/5)+sin^2(2π/5))= =1-cos^2(2π/5)*1= =sin^2(2π/5) О т в е т. 1/4