11.
sin(α+180度)*cos(-α)*sin(-α-180度)
=[- sinα]*cos(-α)*[-sin(-α)
=[- sinα]*[cos(α)]*[sin(α)]
=-[sinα]^2*[cos(α)]
2.
(sin(-α))立方*cos(2π+α)*tan(-α-π)
=(-sina)^3*cosa*tan(-a)
=-(sina)^3*cosa*(-tana)
=(sina)^3*cosa*sina/cosa
=(sina)^4