设x=1+(1/2)^2006,y=1+(1/2)^-2006,求x/y的值

设x,y满足约束条件x+y>=1,x-y>=-1,2x-y 设x,y满足约束条件x+y>=1,x-y>=-1,2x-y 设y=xlnx/1+x^2, 设x大于1,y大于0,x^y+x^-y=2根号二,x^y-x^-y等于? 设y=ln(1-2x),则y''(0). 设y=ln(1+2x),则y(0) 设y=ln(1-2x),则y''(0)... 设y=sinx²+sin²x,求y'rt设y=ln(2x+1)，求y 设x>0,y>0,x+y=1,求8/x+2/y的最小值 设随机变量（X,Y)~f(x,y)=1,0 设随机变量(X.Y)～f(x,y)=1,0 设y=x/1+根号下x,求y' 设y=x/1+根号下x,求y' 3.设y=(1+x^2)arctanx,求y ,y/x=1 . 设f(x,y)=ln[x(1+2/y)],则y偏导等于 设变量x y满足约束条件x-y≥-1 x+y≥1 2x-y≤1 z=(x-2y)/(x+y)的最大值 设x.y满足条件y>=0.X-Y+1>=0.x+y-3 设y=（x/1-x)^x,求dy/dx