当x趋向于圆周率时,求:(x-圆周率)tan(圆周率/2)的极限

当x趋向于圆周率时,求:(x-圆周率)tan(圆周率/2)的极限
当x趋向于圆周率时,求:(x-圆周率)tan(圆周率/2)的极限

当x趋向于圆周率时,求:(x-圆周率)tan(圆周率/2)的极限
(x-pi)tan(x/2)=(x-pi)/tan((pi-x)/2)
令y=pi-x, 上式化为y/tan(-y/2), 当y→0时,极限为-2