Question

第十题！！！！！help！SOS！

Answer 1

(1+sina-cosa)/sina*(1+sinb-cosb)/sinb
=(1+(1-cosa)/sina)*(1+(1-cosb)/sinb)
=(1+tan(a/2))+(1+tan(b/2))
=1+tan(a/2)+tan(b/2)+tan(a/2)tan(b/2)=2
tan(a/2)+tan(b/2)=1-tan(a/2)tan(b/2)
tan(a/2)+tan(b/2)/(1-tan(a/2)tan(b/2))=1
tan(a/2+b/2)=1
a/2+b/2=π/4(a,b是锐角)
a+b=π/2
tanatanb=1

追问

(1+sina-cosa)/sina*(1+sinb-cosb)/sinb
=(1+(1-cosa)/sina)*(1+(1-cosb)/sinb)
这步为什么

懂了

懂了。谢谢〜