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用MATLAB求下列函数的极小点

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用MATLAB求下列函数的极小点
第1),2)题的初始点可任意选取,
第3)题的初始点取为 X0=(0,1)T.
(1)
[x,feval]=fminunc(@(x)x(1)^2+4*x(2)^2+9*x(3)^2-2*x(1)-18*x(2),[3 1 2])
Warning: Gradient must be provided for trust-region method;
using line-search method instead.
> In fminunc at 356
Local minimum found.
Optimization completed because the size of the gradient is less than
the default value of the function tolerance.

x =
1.0000 2.2500 0.0000
feval =
-21.2500
(2)
[x,feval]=fminunc(@(x)x(1)^2+3/2*x(2)^2-2*x(1)*x(2)-x(1)+2*x(2),[1 2])
Warning: Gradient must be provided for trust-region method;
using line-search method instead.
> In fminunc at 356
Local minimum found.
Optimization completed because the size of the gradient is less than
the default value of the function tolerance.

x =
-0.5000 -1.0000
feval =
-0.7500
(3)
[x,feval]=fminunc(@(x)(x(1)-1)^4+x(2)^2,[0 1])
Warning: Gradient must be provided for trust-region method;
using line-search method instead.
> In fminunc at 356
Local minimum found.
Optimization completed because the size of the gradient is less than
the default value of the function tolerance.

x =
1.0045 -0.0000
feval =
4.0848e-010