COS[-2a+π/2]=(1/2)-1=-1/2,而且COS(-2a+π/2)=COS(2a-π/2)=SIN2a
sin(α-3/4π)cos(α-π/4=-1/4),求cos4α的值
0
0
4个回答
-
00
更多回答
相关问题
-
若sin(π-α)+cos(2π-α)=1 ,则sin4α+cos4α+sin(π+α)·cos(4π-α)的值为___00
-
sin(3π+α )=1/4,求cos(π+α)/cosα[cos(π+α)-1]+cos(α-2π)/cos(α+2π00
-
已知sin(π/4+α)sin(π/4-α)=1/6,α∈(π/2,π).求sin4α/1+cos^2α的值00
-
已知cos(π/4-α)=1/3则cos²(3π/4+α)-sin(π/4+α)的值为00
-
sinαcosα=1/8且π/4〈α〈π/2,则cos^4α-sin^4α的值等于?00
-
急救 已知cos(π/4-α)=1/3,求2sin(π/4+α)+cos(3π/4+α)-sin^2(α-π/4) 快来00
-
已知tan(π+α)=3 求2cos(π-α)-3sin(π+α)/4cos(-α)+sin(2π-α)的值00
-
sin(3π-α)=根号sinα+cosα=根号2/4.0<α<π,求-sinα-cosα的值……00
-
证明[2-2sin(α+3π/4)cos(α+π/4)]/(cos^4α-sin^4α)=(1+tanα)/(1-tan00
-
若8cos(π/4+α)×cos(π/4-α)=1,则sin4α+cos4α=00