Question

【(sin a+cos a)/(sin a-cos a) 】=3,tan (a-b)=2,tan (b-2a)=?

Answer 1

第一个条件=>(tana+1)/(tana-1)=3,tana=2

tan(2a-b)=tan(a+a-b)

=(tana+tan(a-b))/(1-tanatan(a-b))

=-4/3

tan(b-2a)=4/3