lim(x趋向0)ln cot x|lnx等于?

lim(x趋向0)ln cot x|lnx
=
lim(x趋向0)[1/ cot x ·(-csc²x)]/(1/x)
=-lim(x->0)x/sinxcosx ( 因为cosx->1,x/sinx->1)
=-11/ cot x ·(-csc²x)]为什么等于1/sinxcosxcscx=1/sinxcsc²x=1/sin²xcotx=cosx/sinx1/cotx=sinx/cosx1/ cot x ·(-csc²x)=sinx/cosxsin²x=1/sinxcosx