讨论下列函数的有界性：(1) (x)=dfrac (x)(1+{x)^2}-|||-(2) (x)=dfrac (1+{x)^2}(1+{x)^4}

int dfrac ({x)^3}({(1+{x)^2)}^2}dx=A.int dfrac ({x)^3}({(1+{x)^2)}^2}dx=B.int df

(int )_(-1)^1(dfrac (sin x+1)(1+{x)^2}+(x)^4)dxA (int )_(-1)^1(dfrac (sin x+1)(

已知(x)=dfrac (xcos x)(1+{x)^4}+(x)^2-(int )_(-1)^1f(x)dx,则(x)=dfrac (xcos x)(1+{x

dfrac (2x)(1+{x)^2}

lim _(xarrow 0)((dfrac {1+{2)^x}(2))}^dfrac (1{x)}= __

(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)}]

int dfrac ({(1-x))^2}(x(1+{x)^2)}dx

已知(x-dfrac (1)(x))=dfrac ({x)^3-x}(1+{x)^4}-|||-__，求(x-dfrac (1)(x))=dfrac ({x)^

( 单选题 ) int dfrac ({e)^x}(1+{e)^2x}dx=_________int dfrac ({e)^x}(1+{e)^2x}dx=int