请高手来解决下这题数学lim xsin(2x/x^2+1) ,x趋向于∞

lim(a^x-a^sinx)/(xsin^2x) ,x趋向于0. lim(x→∞)[sinx/x+xsin(1/2x)] 那位数学高手lim（x趋向于π/2）{in(sinx)}/(π-2x)^2怎么变成lim（x趋向于π/2）{sinx-1 求lim x趋向于0(arctanx)/(x^2+1) lim(1-2^x)^sinx x趋向于－0 lim（x趋向于0）（1-cosx)/x^2 求极限lim{[(sinx)/x]+xsin(1/2x)} lim((1+x)^5-(1+5x))/(x^2+x^5) x趋向于0 lim x趋近于无穷xsin(k/x)-(2x+1)/(x-1) 等于1求k lim f(x)=A x趋向于a limf(x^2)=A x趋向于a^2/1 文科高数题目lim[1/(x+1)-3/(x^3+1)] x趋向于-1 lim[(e^2x-1)/x] x趋向于0 没学 求极限问题{x趋向于无穷大} lim[(2x-1)/(2x+1)]^(x+1),