21.计算极限 lim _(xarrow {0)^+}dfrac (ln tan 5x)(ln tan 2x)

(2) lim _(xarrow 0)[ dfrac (1)(ln (1+{tan )^2x)}-dfrac (1)(ln (1+{x)^2)}]

(2) lim _(xarrow 0)[ dfrac (1)(ln (1+{tan )^2x)}-dfrac (1)(ln (1+{x)^2)}]

5.求极限 lim _(xarrow 0)dfrac ({tan )^2x-(x)^2}({x)^2(tan )^2x}

1.求极限 lim _(xarrow 0)dfrac (tan x-x)(ln (1+{x)^3)}

lim _(xarrow 0)dfrac (tan 5x)(3x)=dfrac (5)(3) ()

求极限lim _(xarrow 0)dfrac (ln (1+x))(2x)求极限

lim _(xarrow pi )dfrac (sin 3x)(tan 5x)。。

lim _(xarrow pi )dfrac (sin 3x)(tan 5x);;

求极限；（3）lim _(xarrow 0)dfrac (sin 2x)(sin 5x)；求极限；（3）；

求极限 lim _(xarrow 0)dfrac (ln (1+{x)^2)-ln (1+(sin )^2x)}(x{sin )^3x}