1.化简(1+cosa-sina)/(1-cosa-sina)+(1-cosa-sina)/(1+cosa-sina)
来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/08/28 05:13:50
1.化简(1+cosa-sina)/(1-cosa-sina)+(1-cosa-sina)/(1+cosa-sina)
2.求tan20+4sin20的值
3.求证:tanx+1/cosx=tan(x/2+∏/4)
4.已知sina=4/5,cos(a+b)=-3/5,a、b∈(0,∏/2)则sinb=
2.求tan20+4sin20的值
3.求证:tanx+1/cosx=tan(x/2+∏/4)
4.已知sina=4/5,cos(a+b)=-3/5,a、b∈(0,∏/2)则sinb=
(1+cosa-sina)/(1-cosa-sina)+(1-cosa-sina)/(1+cosa-sina)=2sina/(cos^2a-1) 这部分没问题是对的 但后面错了 最后=2sina/(1-sin^2a-1)=-2/sina
tan20'+4sin20'=(sin20+2sin40)/cos20=
(sin20+sin40+sin40)/cos20=
(2sin30cos10+sin40)/cos20=
(cos10+sin40)/cos20=
(sin80+sin40)/cos20=2sin60cos20/cos20=2sin60=根号3
secx-tanx=1/cosx-sinx/cosx=(1-sinx)/cosx
=(coxx/2-sinx/2)^2/(cosx/2)^2-(sinx/2)^2
=(coxx/2-sinx/2)/(coxx/2-sinx/2)
tan(π/4 - x/2)=(1-tanx/2)/(1+tanx/2)
=(coxx/2-sinx/2)/(coxx/2-sinx/2)
∴secx - tanx = tan(π/4 - x/2)
sinA+sinB)(sinA+sinB)=1+2sinAsinB=9/25
sinAsinB=-8/25
(cosA+cosB)(cosA+cosB)=1+2cosAcosB=16/25
cosAcosB=-9/50
cos(A-B)=cosAcosB+sinAsinB=-1/2
SIN(A+B)+COS(A+B)=或者=根号2倍的cos(A+B-45度)=根号2倍的[cos(A+B)cos45度+sin(A+B)sin45]
=1/2[cos(A+B)+sin(A+B)]
=2分之根号2倍的cos0
=2分之根号2
tan20'+4sin20'=(sin20+2sin40)/cos20=
(sin20+sin40+sin40)/cos20=
(2sin30cos10+sin40)/cos20=
(cos10+sin40)/cos20=
(sin80+sin40)/cos20=2sin60cos20/cos20=2sin60=根号3
secx-tanx=1/cosx-sinx/cosx=(1-sinx)/cosx
=(coxx/2-sinx/2)^2/(cosx/2)^2-(sinx/2)^2
=(coxx/2-sinx/2)/(coxx/2-sinx/2)
tan(π/4 - x/2)=(1-tanx/2)/(1+tanx/2)
=(coxx/2-sinx/2)/(coxx/2-sinx/2)
∴secx - tanx = tan(π/4 - x/2)
sinA+sinB)(sinA+sinB)=1+2sinAsinB=9/25
sinAsinB=-8/25
(cosA+cosB)(cosA+cosB)=1+2cosAcosB=16/25
cosAcosB=-9/50
cos(A-B)=cosAcosB+sinAsinB=-1/2
SIN(A+B)+COS(A+B)=或者=根号2倍的cos(A+B-45度)=根号2倍的[cos(A+B)cos45度+sin(A+B)sin45]
=1/2[cos(A+B)+sin(A+B)]
=2分之根号2倍的cos0
=2分之根号2
化简(sina+cosa-1)(sina-cosa+1)/sin2a
化简(1+cosa+sina)/(1+sina-cosa)
化简(1+sina-cosa)/(1+sina+cosa)
化简cosa*根号下(1-sina/1+sina)+sina*根号下(1-cosa/1+cosa)
(1+sina-cosa)/(1-sina+cosa)等于多少?
(cosa-sina)/(cosa+sina)=(1-tana)/(1+tana)
同角三角函数 习题证明2(cosa-sina )/1+cosa+sina=cosa/1+sina-sina/1+cosa
化简,1-sinA/cosA
1-sina/cosa 化简
化简,(1+sina-cosa)/(1+sina+cosa)+(1+sina+cosa)/(1+sina-cosa).答
化简1+cosa-sina/1-cosa-sina+1-cosa-sina/1+cosa-sina(要过程)
求证:1+sina+cosa/1+sina-cosa+1-cosa+sina/1+cosa+sina=2/sina