若锐角a,b满足tana*tanb=13/7,sin(a-b)=根5/3,cos(a+b)=

cos(a+b)=cosa*cosb-sina*sinb只需要求出cosa*cosb和sina*sinb的值即可tana*tanb=(sina/cosa)*(sinb/cosb)=(sina*sinb)/(cosa*cosb)所以(sina*sinb)/(cosa*cosb)=13/7 ①sin(a-b)=√5/3可根据sin^(a-b)+cos^(a-b)=1...