lim(X—>0)(1/(x+1)-1)/2x为什么等于-1/2啊

lim(x—0) (1-cosx)/x lim(1-x)^(2/x) x->0 ｜1-x｜lim ————x->0 x lim(0-∞)/(x+1) lim(x->0+)(1/x)^tanx lim(x->0+) e^(1/x) 当lim(x-->0)(g(x)) = 0 ,证明 lim (x-->0)(g(x)*sin1/x) = 0lim (x-->0)(sin1/x)不是不存在吗? 还有 为什么lim (x-->0)((sinx)/x) = 1? lim (x-->0)((sinx)/x)不是等于lim (x-->0)((1/x)lim (x-->0)((1/x) * lim (x-->0)((sinx))吗? lim (x-->0 lim(x->1) x^(1/（1-x）) lim(x->0) x^(tanx)的值 lim(x->0)((2-x)/(3-x))^1/x x趋近于0 lim(x+e^x)^1/x lim(x→0)e^x-x-1/x^2 lim（x-3/x+1）^x lim趋向无穷大 X趋于0 Lim(xlnx)=Lim(lnx/(1/x))=Lim(1/x/(-1/x^2))=Lim(-x)=0Lim(lnx/(1/x))=Lim(1/x/(-1/x^2))其中这步使怎么转化的? (1) lim(x->正无穷) x-lnx (2) lim(x->0+) cosx^1/x^2 1.x趋向0 lim (cosx-1)/x 2.x趋向0 lim sinx/x 求极限lim(x→0)sinxsin(1/x);lim(x→∞)(arctanx/x) lim[(x-1)/(x+1)]^x lim (e-(1+x)^(1/x))/x