已知sin(a-π/3)=1/3,则cos(a+π/6)等于
2个回答
cos(a+π/6)
=sin[π/2-(a+π/6)]
=sin(π/3-a)
=-sin(a-π/3)
=-1/3
相关问题
已知sin(π/3 -a)=1/2,则cos(π/6 +a)=?
已知sin(π/6-a)=1/4,则cos(π/3-2a)=?
已知sin(a-π/3)=1/3,则cos(π/6+a)的值为?
已知sin(π/3-a)=1/3,则cos(π/3+2a)=
sin(π/6-a)=1/3 则 cos(2/3π+2a) 等于什么?
已知sin(π/6+a)=1/3,则cos(2π/3-2a)的值=
sin(a-π/3)=1/3,则cos(π/6+a)=
已知sin(a+π/6)=1/3,且a∈(-π/6,π/3),则(2a+π/3)=
已知sina/cosa=-2,则sin(a-3π)+cos(π-a)/sin(-a)-cos(π+a)
若sin(π/6+a)=1/3,则cos(π/3—a)=_______,cos(2π/3+a)=________