设定义X.上的线性泛函:若x∈Xf（x)求证f是X.上的有界线性泛函,并求||f||.

A . X entails Y B . X presupposes Y C . X is inconsistent with Y D . X is synonymous with Y

A .https://assets.asklib.com/psource/2015102915110662328.jpg B .https://assets.asklib.com/psource/2015102915111923751.jpg C .https://assets.asklib.com/psource/201510291511327285.jpg D .https://assets.asklib.com/psource/2015102915114229647.jpg

A . A B . B C . C D . D

A．x/y*z B．x*(1/(y*z)) C．x/y*1/z D．x/y/z

A:对 B:错

A．e^-x(1-x)+C B．e^-x(1+x)+C C．e^-x(x-1)+C D．-e^-x(1+x)+C

若∫F(x)dx=F(x)+C，则∫XF(x²)dx______；

若∫f(x)dx-cosx+C，则∫xf(x²)dx=______。

如果将“X满足第二可数性公理”改为“X的每一个子空间都是_{<img src='https://img2.soutiyun.com/ask/2020-08-12/966094681303281.png' />}空间”相应的命题是否仍然成立？

设f(x)为[-a，a]上的连续函数，证明： (1)若f(x)是偶函数，则<img src='https://img2.soutiyun.com/ask/2020-10-12/971368555517115.png' />是[-a，a]上的奇函数; (2)若f(x)是奇函数，则<img src='https://img2.soutiyun.com/ask/2020-10-12/971368586317876.png' />是[-a，a]上的偶函数。

设矩阵，<img src='https://img2.soutiyun.com/ask/2020-08-12/966097576187859.png' />X为三阶矩阵，且满足矩阵方程AX+E=A²+X,求矩阵X.

设矩阵<img src='https://img2.soutiyun.com/ask/2020-08-13/966179488479909.png' />,X为三阶矩阵，且满足矩阵方程AX+I=A²+X,求矩阵X.

若∫f(x)dx=F(x)+c，则∫e^-xf(e^-x)dx=( )． <img src='https://img2.soutiyun.com/ask/2020-03-09/952635128499422.png' />

设X是内积空间,X*是它的共轭空间fz表示X上线性泛函fz(x)=＜x,z＞,若X*到X*的映射<img src='https://img2.soutiyun.com/ask/2020-08-13/9661839675971.png' />是一一到上的映射,则X是Hilbert空间.

已知xy=xf(z)+yg(z),xf'(z)+yg'(z)≠0,其中z=z(x,y)是x和y的函数,求证 <img src='https://img2.soutiyun.com/ask/2020-12-09/976380291576342.png' />

设f(x)在(0,+∞)上有意义,x₁＞0,x₂＞0.求证: (1)若<img src='https://img2.soutiyun.com/ask/2021-01-12/979302582932847.png' />单调减少,则<img src='https://img2.soutiyun.com/ask/2021-01-12/979302592723407.png' />; (2)若<img src='https://img2.soutiyun.com/ask/2021-01-12/979302582932847.png' />单调增加,则<img src='https://img2.soutiyun.com/ask/2021-01-12/97930261113346.png' />.

设矩阵<img src='https://img2.soutiyun.com/ask/2021-03-04/983717526085576.png' />且满足AX+E=A²+X.其中E是3阶单位矩阵,求X.

设F是n维欧几里得空间Rⁿ中有界闭集,A是F到自身中的映射,并且适合下列条件:对任何x.γ∈F(x≠γ).有<img src='https://img2.soutiyun.com/ask/2020-08-13/966176163179713.png' /><img src='https://img2.soutiyun.com/shangxueba/ask/50574001-50577000/50576074/spacer.gif' />证明映射A在F中存在唯一的不动点.