Lim x стремится к 0

1 - cos6x/2x*tg2x

X→0 lim (1-cos6x) / (2x· tg2x) = lim[ (2·sin²3x) / [2x· (2tgx / (1-tg²x) ] =

=lim[ (3sin-4sin³x) ²· (1-tg²x) ] / (2x·tgx) =

=lim[sin²x· (3-4sin²x) (1-tg²x) ·cosx] / (2x·sinx) =

=1/2 ·lim[ (sinx) / x] ·lim (3-4sin²x) ·lim (1-tg²x) =

= 1/2·1·3·1 = 3/2