.[1/cos(-α)+cos(180°+ α )]/[1/sin(540°-α)+sin(360°-α)]=tan^3

cos(-α)=cosα,
cos(180°+ α)= -cosα
sin(540°-α)=sinα
sin(360°-α)= -sinα
所以
原式左边
=(1/cosα -cosα) / (1/sinα -sinα)
=(1-cos²α)/cosα / (1-sin²α)/sinα
=(sin²α/cosα) / (cos²α)/cosα
=(sinα/cosα)^3
=tan^3 α
这样就得到了答案