sin(π/6+2π/3)的值为?
sin^2(α)+cosαcos(π/3+α)-sin^2(π/6-α)为定值,要证明
已知cos(α+π/6)-sinα=2√3/3则sin(α-7π/6)的值为
已知sin(x+π/6)=0.25,则sin(5π/6-x)+sin(π/3-x)*sin(π/3-x)的值为多少
若tan(π-α)=2,则2sin(3π+α)cos(5/2π+α)+sin(3/2π-α)sin(π-α)的值为?
若cos2α/sin(α-π/4)=-√2/2,则cosα+sinα的值为?
当x趋向π lim (sin 3x )/( sin 2x) 的极限为?
已知sina=3/5,则sin(π/2+2a)的值为
已知tan(3π-α)=2,则sin(-3π+α)+cos(π-α)/-cos(π+α)+sin(-α)的值为
sin(6/π-α)=1/3,则cos(2π/3+2α)的值为
已知α∈(0,π|2),2tanα+3sinβ=7,且tanα-6sinβ=1,求sinα的值
设α为第一象限的角,且sinα=3/5,求(sin(π+α)+cos(5π-α))/(sin(α-6π)+2cos(2π
求证sin^2α+cosαcos(π/3+α)-sin^(π/6-α)的值与α无关