设L为|x|+|y|=1正向一周,则 https://assets.asklib.com/psource/2015102616184650790.jpg (-ydx+xdy)/(|x|+|y|)的值为:() https://assets.asklib.com/psource/2015102616184896461.jpg
设L是圆周x 2 +y 2 =a 2 (a>0)负向一周,则曲线积分 https://assets.asklib.com/psource/2015102616160584974.jpg (x 3 -x 2 y)dx+(xy 3 -y 3 )dy的值为:()
设函数<img src='https://img2.soutiyun.com/latex/latex.action' />,则y有( ).
设函数z=ysin(xy)+(1-y)arctanx+e<sup>-2y</sup>,则<img src='https://img2.soutiyun.com/latex/latex.action' />=( )
设D为xOy平面上的圆扇形域:x<sup>2</sup>+y<sup>2</sup>≤R<sup>2</sup>,x≥0,y≥0,求二重积分<img src='https://img2.soutiyun.com/ask/2020-09-25/969889852355131.png' />
一家追求利润最大化的企业使用两种要素X<sub>1</sub>与X<sub>2</sub>生产产品Y。生产函数为<img src='https://img2.soutiyun.com/ask/2019-12-05/944397577720965.png' />。已知两种要素的价格分别为1和2,产品Y的价格为4。如果产品Y的价格由4涨到6,而其他条件不变,则下列说法不正确的是( )。
设随机变量(X,Y)的密度函数为<img src='https://img2.soutiyun.com/latex/latex.action' />
设随机变量X~N(μ,1),Y~χ<sup>2</sup>(n),又X,Y相互独立,令<img src='https://img2.soutiyun.com/ask/uploadfile/6129001-6132000/c9a830a559f4268bd58657d7c3aa00fc.png' />,则下列结论正确的是()。
设<img src='https://img2.soutiyun.com/ask/2020-03-11/952811239855432.png' />,则x=1是f(x)在区间[-2,2]上的( ).
设二维随机变量(X,Y)的分布函数为<img src='https://img2.soutiyun.com/ask/uploadfile/6663001-6666000/45f51949890b44017e315c766cce4df5.png' />,则常数A,B分别为( ).
设<img src='https://img2.soutiyun.com/latex/latex.action' />(n=1,2…),则E(X)=( ).
设函数g(x)=1+x,且当x≠0时,<img src='https://img2.soutiyun.com/ask/2020-02-18/950885721858992.png' />,则<img src='https://img2.soutiyun.com/ask/2020-02-18/950885746436467.png' />等于( )
设随机变量X的概率密度为<img src='https://img2.soutiyun.com/latex/latex.action' />,则E(X)=( )
设L是圆周x<sup>2</sup>+y<sup>2</sup>=a<sup>2</sup>(a>0)负向一周,则曲线积分<img src='https://img2.soutiyun.com/shangxueba/ask/17682001-17685000/17682241/2015102616160584974.jpg' />(x<sup>3</sup>-x<sup>2</sup>y)dx+(xy<sup>3</sup>-y<sup>3</sup>)dy的值为:()
设参数方程<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17672290/2015102617310076340.jpg' />,确定了y是x的函数,f″(t)存在且不为零,则d<sup>2</sup>y/d<sup>2</sup>x的值是:()
L是区域D:x<sup>2</sup>+y<sup>2</sup>≤-2x的正向周界,则<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17672639/201510261612581150.jpg' />(x<sup>3</sup>-y)dx+(x-y<sup>2</sup>)dy等于:()
设直线L1:4x+y-4=0,L2:2x-8y+15=0,<img src='https://img2.soutiyun.com/shangxueba/ask/18735001-18738000/18736916/2016071615331659182.jpg' />为曲线C:y=<img src='https://img2.soutiyun.com/shangxueba/ask/18735001-18738000/18736916/2016071615331885551.jpg' />上的一点,则()
设题图中二极管D正向压降不计,则电路中电流I=( )。<img src='https://img2.soutiyun.com/ask/2020-01-13/947775311087877.png' />
设D={(x,y){x<sup>2</sup>+y<sup>2</sup>≤4),二重积分<img src='https://img2.soutiyun.com/shangxueba/ask/18726001-18729000/18727910/2016071616340816183.jpg' />,则()
设函数f(x)一阶连续可导.且f(0)=f&39;(0)=1,则<img src="https://img2.soutiyun.com/ask/2020-12-11/976544786128219.png"/>=().
设随机变量(X,Y)的分布律为 <img src="https://img2.soutiyun.com/shangxueba/ask/19434001-19437000/19435034/c33cb56-chaoxing2016-268566.png"/>则P{X=2|Y=2}=()
设L是从A(1,0)到B(-1,2)的线段,则曲线积分<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17672554/201510271143115588.jpg' />(x+y)ds等于:()
设L为正向圆周x^2+y^2=2在第一象限中的部分,则曲线积分∫Lxdy-2ydx的值为()
设A-(2)B-1.2.3.4.5).A到B的关系R={(x,y)|x∈A,y∈B且x+1-y},则R=().<img src='https://img2.soutiyun.com/shangxueba/ask/68967001-68970000/68967597/994768172395882.png' />