
2
21212121
2
1
2
4h
)hx,hx(f)hx,hx(f)hx,hx(f)hx,hx(f
xx
)x(f −+−+−−−−+++
≈
∂∂
∂
1
2
2
2
1
2
xx
)x(f
xx
)x(f
∂∂
∂
≡
∂∂
∂
2
21212121
2
2
2
4
2222
h
)hxx(f)hxx(f)hxx(f)hxx(f
x
)x(f +−−−−++
≈
∂
∂
where h is given from a rule of thumb (see [4] page 103),
4
1 ∈= )|,xmax(|h
Having in mind the above, write a script with the name: FunctionMin.m that
will do the following:
• Make the 3D – surface and the contour plots of the function:
)yxyyx(e)x,x(f
x
12424
22
21
++++=
in the area
.y,x
. The function should be saved in an m-file
with the name:
f
f
u
u
n
n
T
T
o
o
M
M
i
i
n
n. Given that you have created the m-file with
the functional form of the function, to evaluate it at a point use the
build in function:
f
f
e
e
v
v
a
a
l
l. The calling syntax is:
“
f
f
e
e
v
v
a
a
l
l(@funToMin,x)”
where x is a two element row vector (or m-by-2 array) with “x(1)” and
“x(2)” to represent x
1
and x
2
respectively.
• Do a new figure that creates the contour plot of this function, with
the value of the contours to range between 0 and 80 (for example use:
“V=[0:0.25:2, 3:1:10, 20:10:80]”).
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