设$\lim_{x \to 0} \frac{\sin 2x + xf(x)}{x^3} = 1$，则$\lim_{x \to 0} \frac{2\cos x + f(x)}{x^2} = ($ $)$. (A) 0 (B) $-\frac{2}{3}$ (C) $\frac{4}{3}$ (D) $\infty$
8.设lim_(x to 0) (sin 2x + xf(x))/(x^3) = 1,则lim_(x to 0) (2cos x + f(x))/(x^2) =
若 lim_(x to 0) (f(2x))/(x) = 2，则 lim_(x to infty) xf((1)/(2x)) = ( )A. $\frac{1}
11.已知lim_(x to 0) (ln(1+frac(f(x))/(x)))(2^x-1)=3，则lim_(x to 0) (f(x))/(sqrt(1+x
3 类似地，可求下列极限lim_(xto0)((1)/(sin^2)x-(cos^2x)/(x^2));3 类似地，可求下列极限$\lim_{x\to0}\le
求极限lim_(xto0)(xsin x+2cos x-2)/(x^2)-x^(2cos x).2. 求极限$\lim_{x\to0}\frac{x\sin x
求极限 lim_(x arrow 0) (3sin x+x^2cos frac1x)/((1+cos x)ln(1+x))求极限$ \lim_{x \right
3.计算下列极限(1) lim_(x→2)(-2) ;(2) lim_(x→1)(x^3-x^2+x-1) ;21(3)lim_(x→2)(x^2-16)/(x
3.计算下列极限(1) lim_(x→2)(-2) ;(2) lim_(x→1)(x^3-x^2+x-1) ;21(3)lim_(x→2)(x^2-16)/(x
(3)lim_(xto0)(xsin(1)/(x)+(sin2x)/(x))=____(3)$\lim_{x\to0}(x\sin\frac{1}{x}+\fr
lim_(x to 0) (1 - ax)^(2)/(x) = e^3，则a=A. $-3$B. $-\frac{3}{2}$C. $-2$D. $\frac{