Question

:sin(1440°+α)*cos(α-1080°)/cos(-180°-α)*sin(-α-180°)

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Answer 1

原式=sin(4*360°+α)*cos(α-3*360°)/cos[-(180°+α)]*sin[-(α+180°)]=sinαcosα/cos（180°+α）*[-sin（α+180°）]=sinαcosα/cosα*sinα=1