Biomedical Engineering Reference
In-Depth Information
Solution:
2
3
2
3
ð
0
456
8 0 2
12
1
2
1
2
3
2
4
5 ;
T
4
5 :
a
b
¼
a
b
ð
a
b
Þ
Þ¼
10
1
210
15
18
and tr{ a
32.
Frequently n-tuples are considered as functions of coordinate positions x 1 , x 2 , x 3 ,
and time t . In this case the n-tuple is written r ( x 1 , x 2 , x 3 , t ) that means that each
element of r is a function of x 1 , x 2 , x 3 , and t ,
b }
¼
a
b
¼
r
ð
x 1 ;
x 2 ;
x 3 ;
t
Þ¼½
r 1 ð
x 1 ;
x 2 ;
x 3 ;
t
Þ;
r 2 ð
x 1 ;
x 2 ;
x 3 ;
t
Þ; ...;
r n ð
x 1 ;
x 2 ;
x 3 ;
t
Þ:
(A.33)
stand for a total derivative, or a partial derivative
with respect to x 1 , x 2 , x 3 ,or t , or a definite or indefinite (single or multiple) integral,
then the operation of the operator on the n-tuple follows the same rule as the
multiplication of an n-tuple by a scalar (A.9), thus
Again letting the operator
}
}
r
ð
x 1 ;
x 2 ;
x 3 ;
t
Þ¼½}
r 1 ð
x 1 ;
x 2 ;
x 3 ;
t
Þ; }
r 2 ð
x 1 ;
x 2 ;
x 3 ;
t
Þ; ...; }
r n ð
x 1 ;
x 2 ;
x 3 ;
t
Þ:
(A.34)
The following distributive laws connect matrix addition and operator operations:
}ðr þ tÞ¼}r þ}t and
ð} 1 þ} 2 Þ
r
¼} 1 r
þ} 2 r
;
(A.35)
where
} 1 and
} 2 are two different operators.
Problems
A.4.1.
Find the derivative of the n-tuple r ( x 1 , x 2 , x 3 ,
t )
¼
[ x 1 x 2 x 3 ,10 x 1 x 2 ,
x 3 ] T with respect to x 3 .
cosh
a
A.4.2.
Find the symmetric and skew-symmetric parts of the matrix r
s where
r
¼
[1, 2, 3, 4] and s
¼
[5, 6, 7, 8].
A.5 The Types andLinear Transformations
A system of linear equations
r 1 ¼
A 11 t 1 þ
A 12 t 2 þþ
A 1n t n ;
r 2 ¼
A 21 t 1 þ
A 22 t 2 þþ
A 2n t n ;
...
r n ¼
A n1 t 1 þ
A n2 t 2 þ ...þ
A nn t n ;
(A.36)
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