2.求下列极限:-|||-(1) lim _(xarrow 4)dfrac ({x)^4-256}(x-4);-|||-(2) lim _(xarrow 0)dfrac ({e)^2x-(e)^-2x}(sin x)-|||-(3) lim _(xarrow 0)dfrac (cos x-1)(cos 2x-1);-|||-(4) lim _(xarrow 0)dfrac (x-xcos x)(x-sin x);-|||-(5) lim _(xarrow 0)dfrac ({e)^(x^2)-(e)^2-2cos x}({x)^4}-|||-(6) lim _(xarrow 0)dfrac (sqrt {1+2sin x)-x-1}(xln (1+x))-|||-(7) lim _(xarrow dfrac {pi )(2)}dfrac (tan x)(tan 3x)-|||-(8) lim _(xarrow 0)(dfrac (1+x)(1-{e)^-x}-dfrac (1)(x));-|||-(9) lim _(xarrow 0)((dfrac {sin x)(x))}^dfrac (1{{x)^2}}-|||-(10) lim _(xarrow 1)(x)^tan dfrac (pi {2)}x;-|||-(11) lim _(xarrow 1)(dfrac (1)(ln x)-dfrac (1)(x-1));-|||-(12) lim _(xarrow 0)(dfrac (1)({sin )^2x}-dfrac ({cos )^2x}({x)^2});-|||-(13) lim _(xarrow +infty )(sqrt ({x)^2+2x}-x);-|||-(14) lim(cosx)^2-;-|||-arrow dfrac (pi )(2)-|||-(15)lim ((tan x))^2cos x;-|||-arrow dfrac (pi )(2)-|||-(16) lim _(xarrow 0)([ 2-dfrac {ln (1+x))(x)] }^dfrac (1{x)}.