
已知sin(α-π/4)=1/3,则cos(π/4+α)的值为——
1个回答
2011-03-05 · 知道合伙人教育行家
关注

展开全部
sin(α-π/4)=1/3
cos(π/4+α) = sin{π/2-(π/4+α)} = sin{π/4-α} = sin{-(α-π/4)} = -sin(α-π/4)=-1/3
cos(π/4+α) = sin{π/2-(π/4+α)} = sin{π/4-α} = sin{-(α-π/4)} = -sin(α-π/4)=-1/3
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询