1/sin150°×{-(1/cos120°)+(1-cos60°×cos60°)×4}^2

与式=1/sin30°×{1/cos60°+(1-cos60°×cos60°)×4}^2
    =2×(2+sin60°×sin60°×4)^2
    =2×(2+3/4×4)^2
    =2×(2+3)^2
    =2×5^2
    =50

合ってる、、、よね？w