累次积分∫01dx∫x1f(x,y)dy+∫12dy∫02—yf(x,y)dx可写成( ) A: ∫02dx∫x2f(x,y)dy B: ∫01dx∫x2—yf(x,y)dy C: ∫01dx∫x2—xf(x,y)dy D: ∫01dx∫y2—yf(x,y)dy
累次积分∫01dx∫x1f(x,y)dy+∫12dy∫02—yf(x,y)dx可写成( ) A: ∫02dx∫x2f(x,y)dy B: ∫01dx∫x2—yf(x,y)dy C: ∫01dx∫x2—xf(x,y)dy D: ∫01dx∫y2—yf(x,y)dy
设函数f(x,y)连续,则∫12dx∫x2f(x,y)dy+∫12dy∫y4-yf(x,y)dx=( ). A: ∫12dx∫14-xf(x,y)dy. B: ∫12dx∫x4-xf(x,y)dy C: ∫12dx∫14-yf(x,y)dy. D: ∫12dx∫yyf(x,y)dy
设函数f(x,y)连续,则∫12dx∫x2f(x,y)dy+∫12dy∫y4-yf(x,y)dx=( ). A: ∫12dx∫14-xf(x,y)dy. B: ∫12dx∫x4-xf(x,y)dy C: ∫12dx∫14-yf(x,y)dy. D: ∫12dx∫yyf(x,y)dy
【单选题】求y= 的微分dy A. dy=2x dx B. dy=2x C. dy= dx D. dy=
【单选题】求y= 的微分dy A. dy=2x dx B. dy=2x C. dy= dx D. dy=
已知DX=1,DY=2,ρ=0.5,则D(X-2Y)= A: 11 B: 12 C: 13 D: 14
已知DX=1,DY=2,ρ=0.5,则D(X-2Y)= A: 11 B: 12 C: 13 D: 14
已知y=x3-x, 计算在x=2处当Dx等于1时, Dy=______ ,dy=______ ;当Dx等于0.1时, Dy=______ ,dy=______ ;当Dx等于0.01时, Dy=______ ,dy=______ ;
已知y=x3-x, 计算在x=2处当Dx等于1时, Dy=______ ,dy=______ ;当Dx等于0.1时, Dy=______ ,dy=______ ;当Dx等于0.01时, Dy=______ ,dy=______ ;
设,则dy=______.设,则dy=______.
设,则dy=______.设,则dy=______.
A: -dy B: dx C: dx+dy D: dy
A: -dy B: dx C: dx+dy D: dy
设随机变量X与Y相互独立,且EX=μ1,EY=μ2,DX=σ12,DY=σ22,则COV(XY,X)=__________.
设随机变量X与Y相互独立,且EX=μ1,EY=μ2,DX=σ12,DY=σ22,则COV(XY,X)=__________.
隐函数dy与dy/dx有什么区别
隐函数dy与dy/dx有什么区别
求函数的导数dy/dx,和微分dy:y=x√1-x
求函数的导数dy/dx,和微分dy:y=x√1-x