当∠B=∠C时,化简tan【（A+B）/2】+tanC/2...算出角度...
问题描述：
当∠B=∠C时,化简tan【（A+B）/2】+tanC/2...算出角度...
请不要用到cot....
答
a=180-b-c(a+b)/2=(180-c)/2=90-c/2所以原式=tan(90-c/2)+tanc/2=sin(90-c/2)/cos(90-c/2)+sin(c/2)/cos(c/2)=cos(c/2)/sin(c/2)+sin(c/2)/cos(c/2)=[cos²(c/2)+sin²(c/2)]/sin(c/2)/cos(c/2)=1/(1/2*sinc...