求lim(x趋近于π)(π-x)tan(x/2)的极限?
问题描述:
求lim(x趋近于π)(π-x)tan(x/2)的极限?
答
π-x 趋近于0;tan(x/2)趋近于∞;lim(x趋近于π)(π-x)tan(x/2)=lim(x趋近于π)(π-x)/ (cos(x/2)/sin(x/2))=(分子分母同时求导)lim(x趋近于π)2*(-1)/(-1/(sin x/2)^2 )=lim(x趋近于π)(-2...