设 有连续导数， ， ， ，且当 时， 与 是同阶无穷小，则k等于（ ）.

A . ∫f（x）dx=f（x） B . ［∫f（x）dx］′=f（x） C . ∫f′（x）dx=f（x）dx D . ［∫f（x）dx］′=f（x）=c

A .https://assets.asklib.com/psource/2015102916345292651.jpg B .https://assets.asklib.com/psource/2015102916350533586.jpg C .https://assets.asklib.com/psource/2015102916352156297.jpg D .https://assets.asklib.com/psource/2015102916353744249.jpg

A . f（0）是f（x）在（-a，A.的极大值，但不是最大值 B . f（0）是f（x）在（-a，A.的最小值 C . f（0）足f（x）在（-a，A.的极大值，也是最大值 D . f（0）是曲线y=f（x）的拐点的纵坐标

设∑是空间有界闭区域Ω的整个边界曲面，函数u(x，y，z)和v(x，y，z)是定义在Ω上的具有二阶连续偏导数的函数，<img src='https://img2.soutiyun.com/latex/latex.action' />分别表示u,v沿∑的外法线方向的方向导数，证明下面的格林第二公式： <img src='https://img2.soutiyun.com/ask/6153001-6156000/9e3cfdc9e02aff0c48a97ca686e4a61e.jpg' />

设<img src='https://img2.soutiyun.com/ask/2021-01-10/979126072378366.png' />其中f(u,v)具有二阶连续偏导数,g(u)具有二阶导数,则<img src='https://img2.soutiyun.com/ask/2021-01-10/979126085741131.png' />=().

设<img src='https://img2.soutiyun.com/ask/2021-01-29/98076540372081.png' />，其中f(t)具有连续导数，且<img src='https://img2.soutiyun.com/ask/2021-01-29/980765415471482.png' />。

设f(x)连续,<img src='https://img2.soutiyun.com/ask/2020-12-13/976723404703983.png' />且<img src='https://img2.soutiyun.com/ask/2020-12-13/976723422284988.png' />(A为常数).求导数φ'(x),并讨论φ'(x)的连续性.

设f(x)有二阶连续导数，f(π)=2，<img src='https://img2.soutiyun.com/ask/2021-01-13/979408566018361.jpg' />求f(0)。

设<img src='https://img2.soutiyun.com/ask/2020-08-07/965660038068891.png' />其中f的偏导数连续,求<img src='https://img2.soutiyun.com/ask/2020-08-07/965660050357594.png' />

设函数f(x)和g(x)在[0,1]上有连续导数,且f(0)=0,f'(x)≥0,g'(x)≥0.证明:对任何a∈[0,1],都有 <img src='https://img2.soutiyun.com/ask/2020-12-13/97672399961901.png' />

设f(x)=2x+3x一2，则当x→0时()． A．f(x)是x等价无穷小 B．f(x)与x是同阶但非等价无穷小 C．f(x)比x更高阶的无穷小 D．f(x)是比x较低阶的无穷小

设函数f(u,v)在R²上具有二阶连续偏导数。证明:函数 <img src='https://img2.soutiyun.com/ask/2021-02-02/981107588858527.png' />

设f(x)在x=x₀的邻近有连续的二阶导数,证明 <img src='https://img2.soutiyun.com/ask/2020-10-28/972750844252307.png' />

设<img src='https://img2.soutiyun.com/ask/2020-11-02/973192351945649.png' />,其中f具有连续偏导数,g可导,求<img src='https://img2.soutiyun.com/ask/2020-11-02/973192369901676.png' />.

设f(x)为<img src='https://img2.soutiyun.com/ask/2021-02-02/981112914240121.png' />上以2π为周期，且具有二阶连续导数的函数, 记 <img src='https://img2.soutiyun.com/ask/2021-02-02/981112923970678.png' /> <img src='https://img2.soutiyun.com/ask/2021-02-02/981112932118144.png' />

当x→0时,<img src='https://img2.soutiyun.com/ask/2020-12-14/976803166499552.png' />与x°a(a＞0)是同阶无穷小量,则a=(). A5 B.4 C.5/2 D.2

设f(t)在区间(a,b)上具有连续导数，<img src='https://img2.soutiyun.com/ask/2021-01-28/980701134945681.png' />.定义D上的函数。 <img src='https://img2.soutiyun.com/ask/2021-01-28/980701153716755.png' /> <img src='https://img2.soutiyun.com/ask/2021-01-28/980701165529431.png' />

设f(x)单调下降，<img src='https://img2.soutiyun.com/ask/2021-01-25/98043920905966.png' />如果导数f'(x)在[0,+∞)上连续，那末积分<img src='https://img2.soutiyun.com/ask/2021-01-25/980439230777902.png' />收敛

设f(x,y)具有连续偏导数,且满足<img src='https://img2.soutiyun.com/ask/2021-01-10/979124316503936.png' />求<img src='https://img2.soutiyun.com/ask/2021-01-10/979124324709406.png' />.

.设函数u=f(x,y,z)有连续偏导数，且<img src='https://img2.soutiyun.com/ask/2021-01-02/978463716012693.png' />是由<img src='https://img2.soutiyun.com/ask/2021-01-02/978463730334512.png' />所确定的隐函数，求du.

设ƒ(χ)在[a,b]上连续,则<img src='https://img2.soutiyun.com/ask/2020-08-30/967622223484259.png' />与<img src='https://img2.soutiyun.com/ask/2020-08-30/967622239799192.png' />是χ的函数还是t与u的函数？它们的导数存在吗？如果存在等于什么？

考虑下列修正的牛顿公式(单点Steffensen方法) <img src='https://img2.soutiyun.com/ask/2020-09-10/968583151416147.png' /> 设f(x)有二阶连续导数,<img src='https://img2.soutiyun.com/ask/2020-09-10/968583169623188.png' />试证明该方法是二阶收敛的.