>> fun=inline('x(1)^2+4*x(2)^2+9*x(3)^2-2*x(1)+18*x(2)','x')
>> [x,f]=fminsearch(fun,[0,0,0])
x =
1.0000 -2.2500 0.0000
f =
-21.2500
x1=1.0000 ; x2=-2.2500 ; x3=0.0000
2);3)方法同1)