Youmustattendthemeetingatteno'clockasitisscheduled—notaminuteearlyorlate．A．accuratelyB．punctuallyC．flexiblyD．approx
You must attend the meeting ____ at ten o'clock as it is scheduled — not a minute early or late ．
A ． accurately B ． punctually C ． flexibly D ． approximately
B
在关系模式R(U)中,X U,Y U,X→Y,且Y不能决定X,则Y与X之间的关系是( )。 2020-05-24 …
协方差等于零能推出相互独立吗？∵cov(X，Y)=0又∵cov(X，Y)=E(XY)－E(X协方差 2020-06-10 …
已知x/y+z+u=y/z+u+x=z/u+x+y=u/x+y+z,求（y+x/z+u）+（y+z 2020-06-12 …
已知u=f（x,y）满足r（δu/δr）=x,δu/δθ=y,这里（θ,r）为极坐标.求δu/δx 2020-06-27 …
设函数u（x，y）有连续偏导数，试用极坐标与直角坐标的转化公式x=rcosθ，y=rsinθ，将x 2020-07-08 …
xu-yv=0,yu+xv=1方程两边分别对x求导xu-yv=0,yu+xv=1方程两边分别对x求 2020-07-13 …
设u=(x-y)(y-z)(z-x),证明αu/αx+αu/αy+αu/αz=0 2020-07-26 …
求曲线y=e∧x上与y=x平行的曲线方程.∵y'=（e∧x）'=e∧x令y'=1,解出x=0∴切点 2020-08-01 …
求函数y=（e^x-1）/(e^x+1)的值域？！～网上某个人的回答e^x-1=y(e^x+1)e^ 2020-10-31 …
[ln(x+e^x)]/x=lim(x->0)(1+e^x)/(x+e^x)怎么得到的?原题limx 2020-11-01 …