当|x|较小时,证明下列近似公式:-|||-(1) sin xapprox x :-|||-(2) ^xapprox 1+x ;-|||-(3) sqrt [3](1+x)approx 1+dfrac (x)(n)

当|x|较小时,证明下列近似公式:-|||-(1) sin xapprox x ;-|||-(2) ^xapprox 1+x;-|||-(3) sqrt [n]

(7) lim _(xarrow infty )dfrac (sqrt {1+x)-1}(sqrt [3]{1+x)-1}

=dfrac (sqrt {1+x)-sqrt (1-x)}(sqrt {1+x)+sqrt (1-x)}

int_(1)^sqrt(3) dfrac(d x)(x^2 sqrt(1+x^2))$ \int_{1}^{\sqrt{3}} \dfrac{d x}{x^{

(9) =dfrac (sqrt {1+x)-sqrt (1-x)}(sqrt {1+x)+sqrt (1-x)} ;

lim _(xarrow 1)dfrac (sqrt {3-x)-sqrt (1+x)}({x)^2-1}-|||-__

[题目] lim _(xarrow 1)dfrac (sqrt {3-x)-sqrt (1+x)}({x)^2+x-2}= __

A.sqrt(1+x) B.(sqrt(1+x))/(2) C.(sqrt(1+x))/(sqrt(x)) D.(sqrt(1+x))/(2sqrt(x)

2.lim _(xarrow 1)dfrac (sqrt {3-x)-sqrt (1+x)}({x)^2+x-2}=2.

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