Question

化简tan(π+α)*cos(2π-α)*sin(-α+3π/cos(-α-π)2)/sin(-π-α)

tan(π+α)*cos(2π-α)*sin(-α+3π/2）/cos(-α-π)/sin(-π-α)

Answer 1

tan(π+α)*cos(2π-α)*sin(-α+3π/2）/cos(-α-π)/sin(-π-α)
=tanα*cosα*(-cosα)/(-cosα)/(sinα)
=tanα*cosα/sinα
=tanα/tanα
=1

Answer 2

tan(π+α)*cos(2π-α)*sin(-α+3π/2）/[cos(-α-π)/sin(-π-α)]
= tanα. cosα . (-cosα) /[ -cosα/ sinα]
= [sinα]^2