Question

用洛必达法则求下列极限 lim x->0+(ln tan7x)/(ln tan2x)

用洛必达法则求下列极限
lim x->0+(ln tan7x)/(ln tan2x)
lim(x->1) (1-x^2)*tan[(兀/2)*2]怎么用洛必达求

Answer 1

lim x->0+(ln tan7x)/(ln tan2x)
=lim( x->0)[7sec^2(7x) /tan7x]/[2sec^2(2x)/tan2x] (sec7x→1）
=lim( x->0)7tan(2x)/[2tan(7x)]
=1