tan[(a+b)/2]等于什么
来源:学生作业帮 编辑:神马作文网作业帮 分类:数学作业 时间:2024/09/21 18:33:28
tan[(a+b)/2]等于什么
答案1:按公式tan(A+B) = (tanA+tanB)/(1-tanAtanB)展开
tan[(a+b)/2]=tan(a/2+b/2)=(tana/2+tanb/2)/(1-tana/2tanb/2)
答案2:tan(A/2+B/2)=(sinA+sinB)/(cosA+cosB)
sinA+sinB
=sin((A+B)/2+(A-B)/2)+sin((A+B)/2-(A-B)/2)
=sin(A+B)/2 *cos(A-B)/2
cosA+cosB
=cos((A+B)/2+(A-B)/2)+cos((A+B)/2-(A-B)/2)
=cos(A+B)/2 *cos(A-B)/2
(sinA+sinB)/(cosA+cosB)
=[sin(A+B)/2 *cos(A-B)/2 ]/[cos(A+B)/2 *cos(A-B)/2]
=[sin(A+B)/2]/[cos(A+B)/2]
=tan(A/2+B/2)
tan[(a+b)/2]=tan(a/2+b/2)=(tana/2+tanb/2)/(1-tana/2tanb/2)
答案2:tan(A/2+B/2)=(sinA+sinB)/(cosA+cosB)
sinA+sinB
=sin((A+B)/2+(A-B)/2)+sin((A+B)/2-(A-B)/2)
=sin(A+B)/2 *cos(A-B)/2
cosA+cosB
=cos((A+B)/2+(A-B)/2)+cos((A+B)/2-(A-B)/2)
=cos(A+B)/2 *cos(A-B)/2
(sinA+sinB)/(cosA+cosB)
=[sin(A+B)/2 *cos(A-B)/2 ]/[cos(A+B)/2 *cos(A-B)/2]
=[sin(A+B)/2]/[cos(A+B)/2]
=tan(A/2+B/2)
tan^2a/2等于什么
2(tan a+tan b)
已知tan(a+b)=3,tan(a-b)=5,则tan 2a等于多少?
Tan(兀-a)等于什么
tan(a+b)=3/4,tan(a-π/4)=1/2,那么tan(b+π/4)等于多少
已知tana等于负四分之三,tan(派-b)等于二分之一 求tan(a-2b)
tan(2兀-a)?等于
tan(2a) 等于什么?请问各位怎么证明?
若tan(A+B)=2/5,tan(A-π/4)=1/4,则tan(B+π/4)等于多少?
三角形abc中,已知tan(A)=(1/3),tan(B)=(1/2),则角C等于?
tan(B/2)tan(C/2)+tan(A/2)tan(B/2)+tan(A/2)tan(C/2)= A+B+C=18
tan A:tan B:tan C=1:2:3 求A:B:C