cos(540-α)sin(α-360)/sin(-α+180)cos(180+α)
sinα + cosα
Cos(180°+α)*sin(α+360°)/sin(-α-180°)*cos(-180°-α)
化简cos(540°-α)sin(α-360°)/sin(-α+180°)cos(180°+α)
.[1/cos(-α)+cos(180°+ α )]/[1/sin(540°-α)+sin(360°-α)]=tan^3
sinα-2cosα分之sinα+cosα
若sinα*cosα
已知sinα*cosα
已知sinαcosα
sinα+sinβ=sinγ cosα+cosβ=cosγ 证明cos(α-γ)
已知sinα+sinβ+sinγ=0,cosα+cosβ+cosγ=0.求cos(β
求证:(1/sinα-sin(180°+α))/(1/cos(540°-α)+cos(360°-α))=1/(tanα)
已知3sinα-2cosα=0,求(cosα-sinα)/(cosα+sinα)+(cosα+sinα)/(cosα-s