诱导公式 200分1.化简:sin(30°+α)×tan(45°+α)×tan(45°-α) sec(60°-α)2.求值:sin_数学解答

诱导公式 200分
1.化简:sin(30°+α)×tan(45°+α)×tan(45°-α) sec(60°-α)
2.求值:sin²1°+sin²2°+sin²3°+.+sin²89°
3.已知θ=(0,2π),且sinθ、COSθ是方程X²-KX+K-1=0的根求K和θ的值
4.已知SINα+SINβ+SINr+0,且cosα+cosβ+cosr=0
求证：cos(α-β)= 负的二分之一

人气：417 ℃　时间：2020-04-11 01:02:49

解答

1.化简:sin(30°+α)×tan(45°+α)×tan(45°-α) sec(60°-α)=sin(30°+α)×tan(45°+α)×tan(45°-α)/ cos(60°-α)=sin(30°+α)/[cos(90°-30°-α]×tan(45°+α)×tan(90°-45°-α)=s...