已知0
来源:学生作业帮助网 编辑:作业帮 时间:2024/11/24 01:08:18
x){}K
ll;T̼smJ4m7ҌUW6
(blMMʓA
uQi1jڠqn6>Um
4*gT 2Bc+еyv G bO
已知0
已知0
已知0
sinα=[2tan(α/2)] / [1+(tan α/2)^2] =4/5
cosα=[1-(tan α/2)^2] / [1+(tan α/2)^2] =3/5
sin(β-α)=±√{1 - [cos(β-α)]^2} =±7√2/10
∵0