∫[(x^3+1)/(x^2+1)]dx =∫[x^3/(x^2+1)]dx+∫[1/(x^2+1)]dx =0+2∫[1/(x^2+1)]dx =2(arctanx)| =2*(arctan1-arctan0) =2*[(π/4)-0] =π/2 说明，奇函数在对称区间上的定积分为零；偶函数在对称区间上的积分为其半区间上积分的2倍。
答：dy/dx=1+1/(1+exp(x+y)),d^2y/dx^2=d(dy/dx)/dx=-1/[1+exp(x+y)]^2.exp(x+y).(1+dy/dx...详情>>
答：详情>>
