[题目]若 (dfrac (1)(x))=x, 则 (x)= ()-|||-A、 dfrac (1)(x)-|||-B、 dfrac (1)({x)^2}-||
(B) dfrac (1)(2)(X)_(1)+dfrac (1)(2)(X)_(2)-|||-(C) dfrac (1)(2)(X)_(1)+dfrac (1
定积分 ^2-dfrac (1)(x)+C ()()-|||-A dfrac (1)(2)(x)^2+dfrac (1)(x)+C-|||-B dfrac (1
dfrac (1)(x) C. -dfrac (1)({x)^2} D. dfrac (2)({x)^3}
(2) lim _(xarrow infty )((dfrac {x+1)(x-1))}^-dfrac (x{2)}= () ;-|||-(A)1 (B) ^d
3、设 (x,y)=arctan dfrac (x)(y), 则 (1,1)=-|||-(A)1; (B)0; (C) dfrac {1)(2),dfrac
(B) alpha lt dfrac (1)(2). (C) alpha geqslant dfrac (1)(2), (D) alpha gt dfrac (
2 , 1 B . 1 , 2 C . (x)=dfrac ({e)^x-1}(x), 1D . (x)=dfrac ({e)^x-1}(x), 2设函数,若当
1.设 (dfrac (1)(x))=x((dfrac {x)(x+1))}^2, 则 f(x)= ()-|||-(A) dfrac (1)(x)((dfrac
则 int xf(x)dx= () .-|||-A、 dfrac (1-ln x)({x)^2}+C B、 dfrac (1)(x)+c C、 ln x-x+C