化简 1.sin(α-2π)sin(α+π)-2cos(α-π/2)sin(α-π)-cos²(π/2+α)
(1+sinα+cosα)*[sin(α/2)-cos(α/2)]/√(2+2cosα)化简 (3/2*π
已知(3sinα+cosα)/(3cosα-sinα)=2,则2-3sin(α-3π)sin(1.5π-α)-[cos(
比较大小sin(cosα)与cos(sinα)(0<α<π/2)
α∈(0,π/2 ),比较 sin(cosα) 与cos(sinα)大小
化简 1.sin(α-2π)sin(α+π)-2cos(α-π/2)sin(α-π)-cos²(π/2+α)
α属于(0,π/2)且2sin²α-sinαcosα-3cos²α=0求sin(α+π/4)/sin
化简[sin(π/2-α)cos(π/2-α)]/cos(π+α)-[sin(π-α)cos(π/2-α)]/sin(π
化简sin(α-5π)/cos(3π-α)×cos(π/2-α)/sin(α-3π)×cos(8π-α)/sin(-α-
设f(α)=2sinαcosα+cosα/1+sin²α+cos(3π/2+α)-sin²(π/2+
已知tan(3π+α)=2,求:1、(sinα+cosα)²;2、sinα-cosα/2sinα+cosα
已知tanα=2,sinα+cosα<0,求[sin(2π-α)*sin(π+α)*cos(-π+α)]/[sin(3π
1.证明 cos(α-π/2)=sinα sin(α-π/2)=﹣sinα