讨论 (x)=dfrac (1)(x) 在区间(0,1),(1,2), (2,+infty ) (0,+infty ) 上的有界性.

(1) =dfrac (x+1)(x(x-1)) 在区间 (-1,0) (0,1)、(1,2)、(2,3)上的有界性;

(-2,1)-|||-C.(0,1) D. (-infty ,-2) x (1,+infty )

[题目]试证下列函数在指定区间内的单调性.-|||-(1) =dfrac (x)(1-x) (-infty ,1) ;-|||-(2) =x+ln x (0,+

1、曲线 =3(x)^4-4(x)^3+1 的凸区间是 () ;-|||-(A) (-infty ,0) (B) (1,+infty ) (C) (dfrac

[题目]函数 (x)=dfrac (|x|sin (x-1))(x(x-1)(x-2)) 在下列区间内有界-|||-的是 ()-|||-A.(0,1)-|||-

(2) lim _(xarrow infty )((dfrac {x+1)(x-1))}^-dfrac (x{2)}= () ;-|||-(A)1 (B) ^d

(4) (int )_(0)^+infty dfrac (dx)((1+x)(1+{x)^2)}

2、设f(x)在区间[0,1]上可导, (1)=2(int )_(0)^dfrac (1{2)}(x)^2f(x)dx, 证明:存在 varepsilon in

(int )_(-infty )^+infty (x)^2(e)^-a(x^2)dx=dfrac (1)(2)sqrt (dfrac {pi )({a)^3}}

(int )_(0)^+infty dfrac (x{e)^-x}({(1+{e)^-x)}^2}dx= ()-|||-__