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问函数y=x<sup>2</sup>-(x<0)在何处取得最小值?
问函数y=x<sup>2</sup>-<img src='https://img2.soutiyun.com/ask/2020-12-26/977844522637231.png' />(x<0)在何处取得最小值?
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设x<sup>2</sup>+y<sup>2</sup>+z<sup>2</sup>=yf(z/y),其中f可导,求
设x<sup>2</sup>+y<sup>2</sup>+z<sup>2</sup>=yf(z/y),其中f可导,求<img src='https://img2.soutiyun.com/ask/2020-12-13/976737694328303.png' />
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设f(x)可导,求下列函数的导数(1)y=f(x<sup>2</sup>);(2)y=f(sin<sup>2</sup>x)+f(cos<sup>2</sup>x).
设f(x)可导,求下列函数的导数<img src='https://img2.soutiyun.com/ask/2020-08-05/965495444440789.png' />
(1)y=f(x<sup>2</sup>);(2)y=f(sin<sup>2</sup>x)+f(cos<sup>2</sup>x).
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设z=x<sup>2</sup>+y+f(x-y),且当y=0时,z=e<sup>x</sup>,求函数f和z的表达式.
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设u=f(x,y,z)=x<sup>3</sup>y<sup>2</sup>z<sup>2</sup>,而z是由方程x<sup>2</sup>+y<sup>3</sup>+z<sup>3</sup>-3xyz=0所确定
设u=f(x,y,z)=x<sup>3</sup>y<sup>2</sup>z<sup>2</sup>,而z是由方程x<sup>2</sup>+y<sup>3</sup>+z<sup>3</sup>-3xyz=0所确定的x,y的函数,<img src='https://img2.soutiyun.com/ask/2020-12-13/976737253128068.png' />
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设x=2<sup>1110</sup>·0.101100l1,y=2<sup>111</sup>·011100110,求f(x±y)f(x*y).
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(1)设,而x=ct,y=Int,其中c为常数,求;(2)设.且z=x<sup>2</sup>cosy,求
(1)设<img src='https://img2.soutiyun.com/ask/2020-08-07/965659801705371.png' />,而x=ct,y=Int,其中c为常数,求<img src='https://img2.soutiyun.com/ask/2020-08-07/965659853763349.png' />;
(2)设<img src='https://img2.soutiyun.com/ask/2020-08-07/965659870368299.png' />.且z=x<sup>2</sup>cosy,求<img src='https://img2.soutiyun.com/ask/2020-08-07/965661045699524.png' />
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设f(x,y)=x<sup>2</sup>y<sup>2</sup>-2y,
设f(x,y)=x<sup>2</sup>y<sup>2</sup>-2y,<img src='https://img2.soutiyun.com/ask/2021-01-26/980508854051598.png' />
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设函数y=y(x)由方程e<sup>y</sup>+6xy+x<sup>2</sup>-1=0所确定,求
设函数y=y(x)由方程e<sup>y</sup>+6xy+x<sup>2</sup>-1=0所确定,求<img src='https://img2.soutiyun.com/ask/2020-10-12/971345279192785.png' />
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设f,g,h∈R<sup>R</sup>,且f(x)=x+3,g(x)=2x+1,h(x)=x/2。求
设f,g,h∈R<sup>R</sup>,且f(x)=x+3,g(x)=2x+1,h(x)=x/2。求<img src='https://img2.soutiyun.com/ask/2020-12-21/977407870799794.jpg' />
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设f"(x)存在,求下列函数的二阶导数;(1) y=f(x<sup>2</sup>);(2)y=ln[f(x)].
设f"(x)存在,求下列函数的二阶导数<img src='https://img2.soutiyun.com/ask/2020-11-10/973871310253584.png' />;
(1) y=f(x<sup>2</sup>);(2)y=ln[f(x)].
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设随机变量X与Y独立同分布,且E(X)=μ,Var(X)=σ<sup>2</sup>,试求E(X-Y)<sup>2</sup>.
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已知y<sub>1</sub>(x)=e<sup>x</sup>是齐次线性方程(2x-1)y"-(2x+1)y'+2y=0的一个解,求此方程的通解
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设f(x+y,x-y)=x<sup>2</sup>-y<sup>2</sup>-xy,求f(x,y).
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设u=x<sup>2</sup>-y<sup>2</sup>+xy为调和函数,试求其共轭调和函数v(x,y)及解析函数 f(z)=u(x,y)+iv(x,y)。
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设函数z=x<sup>2</sup>y,则∂<sup>2</sup>z/∂x∂y=()
A.x+y
B.x
C.y
D.2x
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设f(z)=u(x,y)+iv(x,y)为z=x+iy的解析函数,且已知xu(x,y)-yv(x,y)+x<sup>2</sup>-y<sup>2</sup>=0,求函数f(z)。
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考虑微分方程y"+q(x)y=0。(1)设y=φ(x)与y=Ψ(x)是它的任意两个解,试证y=φ(x)与y=Ψ(x)的朗斯基行列式恒等于一个常数。(2)设已知方程有一个特解为y=e<sup>x</sup>,试求这方程的通解,并确定q(x)=?
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设y=ln(x<sup>2</sup>-3x+2),求y<sup>(6)</sup>
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设Ω=|(x,y,z)|x<sup>2</sup>+y<sup>2</sup>+z<sup>2</sup>≤1|则=().
设Ω=|(x,y,z)|x<sup>2</sup>+y<sup>2</sup>+z<sup>2</sup>≤1|则<img src='https://img2.soutiyun.com/ask/2021-01-10/979150367436964.png' />=().
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设函数(f(x,y)=x<sup>2</sup>y+xy<sup>2</sup>,则f(x-y,xy)=()。
A.xy(x-y)(xy+x-y)
B.(x-y)<sup>2</sup>y+x<sup>3</sup>y<sup>2</sup>
C.(x-y)<sup>2</sup>y+x<sup>2</sup>y<sup>2</sup>
D.xy(x-y)<sup>2</sup>(x-y)
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当→2时,y=x<sup>2</sup>→4.问δ等于多少,使当|x-2|<δ时,|y-4|<0.001?.
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设二维随机变量(X,Y)的联合概率密度为求随机变量Z=X<sup>2</sup>+Y<sup>2</sup>的概率密度。
设二维随机变量(X,Y)的联合概率密度为<img src='https://img2.soutiyun.com/ask/2020-11-26/975236663523476.jpg' />
求随机变量Z=X<sup>2</sup>+Y<sup>2</sup>的概率密度。
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(1)求y=Inx+e<sup>x</sup>的反函数x=x(y)的导数;(2)设y=f(x)是x=φ(y)的反函数,且f(2)-4,f(2)=3,f'(4)=1,问φ(4)等于1/3还是1?