sin(a+b)=2/3,sin(a-b)=负1/5,求tana/tanb=

来源:学生作业帮助网 编辑:作业帮 时间:2024/11/19 09:40:58
sin(a+b)=2/3,sin(a-b)=负1/5,求tana/tanb=
xQ;n@ %^o(ddX "jE"hEc|f$yofEøR=m[24ݧ{w68/ԘOu|`FE%ZO5EU0f8 tXL#]d2_߳rU>כ.[rՍ.i> F=rAmOuFFBbeh%ׄs01+rK#tQ:~A/

sin(a+b)=2/3,sin(a-b)=负1/5,求tana/tanb=
sin(a+b)=2/3,sin(a-b)=负1/5,求tana/tanb=

sin(a+b)=2/3,sin(a-b)=负1/5,求tana/tanb=
sin(A+B)=sinAcosB+sinBcosA=2/3 ;sin(A-B)=sinAcosB-sinBcosA=-1/5
所以:sinAcosB=7/30(上面两式相加再除2) ,sinBcosA=13/30(上面两式相减再除2).两个再相除:tanA*cotB=7/13.则:tanA/tanB=7/13.

sin(a+b)=sinacosb+cosasinb=2/3,
sin(a-b)=sinacosb-cosasinb=-1/5
sinacosb=7/30
cosasinb=13/30
tanacotb=7/13
tana/tanb=7/13