sin(a+b)=0.5,sin(a-b)=1/3 则tana/tanb

题目

sin(a+b)=0.5,sin(a-b)=1/3 则tana/tanb

答案

sinacosb+cosasinb=0.5
sinacosb-cosasinb=1/3
解二元一次方程
所以sinacosb=5/12
cosasinb=1/12
tan/tanb
=(sina/cosa)/(sinb/cosb)
=sinacosb/cosasinb
=5