
1.原式=(cosπ/4cosα sinπ/4sinα)^2 (cosπ/4cosα-sinπ/4sinα)^2=1/2(cos^2α sin^2α 2cosαsinα) 1/2(cos^2α sin^2α-2cosαsinα)=1/2 1/2=1第二题同理化简展开也等于1

1.原式=(cosπ/4cosα sinπ/4sinα)^2 (cosπ/4cosα-sinπ/4sinα)^2=1/2(cos^2α sin^2α 2cosαsinα) 1/2(cos^2α sin^2α-2cosαsinα)=1/2 1/2=1第二题同理化简展开也等于1