(3)设 (x)=dfrac (x)(sqrt {{x)^2+1}}, 则 f(f(x))= __ (2012计算机

[题目]设 (dfrac (1)(x))=dfrac (x)({x)^2+1} 则 f(x)=

11.设 (x)=dfrac (x)(sqrt {1+{x)^2}} 求 [ f(x)] , f[ f(x)] .

.已知 (dfrac (1)(x))=dfrac (4)(x)+2(x)^2+1, 求f(x), ((x)^2+1)

2.设函数 (x)=dfrac (1)(x) ,则 f[ f(x)] =

设f（x）=dfrac (2)(3)(x)^3,xleqslant 1 (x)^2,xgt 1，则f（x）在x=1处的（　　）设f（x）=，则f（x）在x=1处

设f（x）=dfrac (2)(3)(x)^3,xleqslant 1 (x)^2,xgt 1，则f（x）在x=1处的（　　）设f（x）=，则f（x）在x=1处

设 (x+dfrac (1)(x))=(x)^2+dfrac (1)({x)^2}, 则 lim _(xarrow 3)f(x)= __

1.设 (x)=dfrac (1)(1-{x)^2}, 求 (-x),f[ f(x)] ,f[ dfrac (1)(f(x))]

设(x)=dfrac (1)(1+{x)^2}+sqrt (1-{x)^2}(int )_(0)^1f(x)dx, 则 (int )_(0)^1f(x)dx=设

[题目]设 (x+dfrac (1)(x))=(x)^2+dfrac (1)({x)^2}, 则f(x)= __