a^3 tan〖45°〗+a^2 b tan〖60°〗+9ab^2 cot^2〖60°〗+2b^3 cos〖60°〗
=a^3 (1)+a^2 b√(3)+9ab^2 (1/3)+2b^3 (1/2)
=a^3+〖√(3) a〗^2 b+3ab^2+b^3
2 cos^2〖45°〗-3a cot〖45°〗+a^2 tan^2〖60°〗-2a^3 sin^2〖45°〗
=2(1/2)-3a(1)+a^2 (3)-2a^3 (1/2)
=1-3a+3a^2-a^3
=-(a-1)^3
4a^2 sin^4〖45°〗-6ab tan^2〖30°〗+(b cot〖45°〗 )^2
=4a^2 (1/4)-6ab(1/3)+(b(1) )^2
=a^2-2ab+b^2
=(a-b)^2
