设函数则时x的取值范围是________.
化简+=________.
已知sin(π-α)=log8,且α∈,则tan(2π-α)的值为________.
已知f(α)=,则f的值为________.
已知α为锐角,且2tan(π-α)-3cos+5=0,tan(π+α)+6sin(π+β)=1,则sin α的值是______.
已知cos=,且|φ|<,则tan φ=______.