lim(x->1/2)sin(1-2x)tanπx

lim tan x - sin x / x³ lim eˆ2x - 1 / x 几道求极限的高数题,lim1/x(tanπx/(2x+1)) x→∞lim x(x^x-1)x→0+lim(x^x^x- 1.lim x→0,(tanx-sinx)/(sin2x)^3 2.lim x→0,sin(x-1)tan(x-1)/2 lim(x趋向0)ln(1+sin x)/x^2 lim(sin(x^2*cos(1/x)))/x怎么做? 求极限lim(x-->0)x^2 sin(1/x), lim√(1+tan)-√1+sin a/[x√(1+sin^2x)-x x趋近0时的极限 lim[x→1] tan(x-1)-sin(x-1) / x-1= lim(tan^3(3x)/(X^2sin(2x))(x趋近于0） 化简(sin^2 x/sin x-cosx)-(sin x+cosx/tan^2 x-1) lim (x→0) ［(2x) / (1+x^2)］/sec x tan x+si 证明(1-2sin x cos x )/(cos^2x-sin^2x)=(1-tan x)/(1+tan x)