Positivo Definitivo de una funcion en Matlab.pdf

3
() = [ 2 () 1 2 2 () 1 2 2 () 2 1 2 () 2 2 ] () = [ 4 −3 −3 4 ] () 1 = 4 1 − 3 2 2 () 1 2 =4 2 () 1 2 = −3 () 2 = −3 1 + 4 2 2 () 2 2 =4 2 () 2 1 = −3 >> syms x1 x2 f = 2*x1^2-3*x1*x2+2*x2^2 f = 2*x1^2 - 3*x1*x2 + 2*x2^2 >> pretty(f) 2 2 2 x1 - 3 x1 x2 + 2 x2 >> fx1 = diff(f,x1,1)

Transcript of Positivo Definitivo de una funcion en Matlab.pdf

  • () =

    [ 2()

    12

    2()

    122()

    21

    2()

    22 ]

    () = [

    4 33 4

    ]

    ()

    1= 41 32

    2()

    12 = 4

    2()

    12= 3

    ()

    2= 31 + 42

    2()

    22 = 4

    2()

    21= 3

    >> syms x1 x2

    f = 2*x1^2-3*x1*x2+2*x2^2

    f =

    2*x1^2 - 3*x1*x2 + 2*x2^2

    >> pretty(f)

    2 2

    2 x1 - 3 x1 x2 + 2 x2

    >> fx1 = diff(f,x1,1)

  • ()

    1=

    2()

    12 =

    2()

    12=

    ()

    2=

    2()

    22 =

    2()

    21=

    () =

    () =

    fx1 =

    4*x1 - 3*x2

    >> pretty (fx1)

    4 x1 - 3 x2

    >> fx1x1 = diff(f,x1,2)

    fx1x1 =

    4

    >> fx1x2 = diff(fx1,x2,1)

    fx1x2 =

    -3

    >> fx2 = diff(f,x2,1)

    fx2 =

    4*x2 - 3*x1

    >> pretty (fx2)

    4 x2 - 3 x1

    >> fx2x2 = diff(f,x2,2)

    fx2x2 =

    4

    >> fx2x1 = diff(fx2,x1,1)

    fx2x1 =

    -3

    >> A=[fx1x1 fx1x2; fx2x1 fx2x2]

    A =

    [ 4, -3]

    [ -3, 4]

    >> det(A)

    ans =

    7

  • () =

    () =

    >> [A,D]=eig([fx1x1 fx1x2; fx2x1 fx2x2])

    A =

    [ 1, -1]

    [ 1, 1]

    D =

    [ 1, 0]

    [ 0, 7]