niantianyux
春芽
共回答了25个问题采纳率:84% 举报
1、y=√(1-x^3) y=√u u=1-x^3 dy/du=1/(2√u) du/dx=-3x^2
y'=dy/du*du/dx
=1/(2√u)*(-3x^2)
=-3/2*x^2/√(1-x^3)
2、lim[x-->+∞](x^2+1)/[x(x+1)]
=lim[x-->+∞](x^2+1)/(x^2+x)
=lim[x-->+∞](1+1/x^2)/(1+1/x) (x-->+∞,1/x--->0)
=1/1
=1
1年前
10