CHAPTER 1Matrices, Vectors, and Vector Calculus 1-1.. Consider the triangle a, b, c which is formed by the vectors A, B, C... The unit vectors in spherical coordinates are expressed in t
Trang 1CHAPTER 1
Matrices, Vectors, and Vector Calculus
1-1
x2 = x2′
x1′ 45˚
x1
x3′
x3
45˚
Axes x′1 and x′3 lie in the x x1 3 plane
The transformation equations are:
Trang 2CHAPTER 1
x1A
B C
D
α β
(4) Therefore,
(5) Thus,
E D
Trang 3Comparing (9) with (7), we find
1
1
C
But,
Trang 4i i
4
Identifying B k i =(B t)ik and A jk =(A t)kj, at./
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Trang 5A A
A
i x
But this can be true only if
ik i k i
There are 4 diagonals:
If L=L′, then
Trang 6component of B along A
B A
Trang 7( )
12
Trang 8b) Consider vectors A and B in the plane defined by e , Since the figure defined by A, B,
1 3 2
= altitude area of the base
= volume of the parallelepiped
Trang 9( ) ( ) ( ) ( )
Trang 10Full file
Trang 11But cosr θ is the magnitude of the component of r along a
component perpendicular to a is arbitrary
constant
⋅ =
r a
This
a plane perpendicular to
⋅ =
r a a
which is the cosine law of plane trigonometry
1-18 Consider the triangle a, b, c which is formed by the vectors A, B, C
A
α C B
γ β
b c
a
1-16.
Trang 13( )
b) Using (3), we can find sin(α β− ):
a) Consider the following two cases:
When i ≠ δij = but 0 εijk ≠ 0When i = j δij ≠ but 0 εijk = 0Therefore,
0
ijk ij ij
ε δ =
When j = k, εijk =εijj= 0Terms such as ε εj11 A11=0 Then,
Trang 15g) i ≠ A or : This implies that i = k or i = j or m = k
Trang 16jl km k jm m j k jkm
Trang 18The unit vectors in spherical coordinates are expressed in terms of rectangular coordinates by
Trang 19d
r dt d
r
θ φ
(
2 2
v k
Trang 201 cos2
r
v k
θ
θθ
Trang 211-29 Let r =2 9 describe the surface S and 1 x y z+ + 2 = describe the surface S The angle 1 θ
between and at the point (2,–2,1) is the angle between the normals to these surfaces at the point The normal to is
2 1
12
Trang 22grad grad grad grad
(3)
or,
4cos
2 1
1 2 2
1 2 2
2
22
r
x r
x x
Trang 231 2 2
f r
f r x
f r
r f
1 2 2
1 2
2
1
j j
i i
j
j i
=
b)
Trang 24where C is the integration constant (a vector)
1-34 First, we note that
Trang 25The rest of the common volume is formed by 8 equal parts from the other cylinder (the one
along the x-axis) One of these parts extends from x = 0 to x = a, y = 0 to y= a2−x2, z = a to
0
88
16
23
a a
3
163
a
1-35.
Trang 26Since ∇ ⋅ , we only need to evaluate the total volume Our cylinder has radius c and height
d, and so the answer is
Trang 27z
y C
The curve C that encloses our surface S is the unit circle that lies in the xy plane Since the
element of area on the surface da is chosen to be outward from the origin, the curve is directed
counterclockwise, as required by the right-hand rule Now change to polar coordinates, so that
we have ds=dθeθ and A=sinθi+cosθk on the curve Since eθ⋅ = −i sinθ and eθ⋅ =k 0, we have
−
= =
−Further, AH=(x−1, ,y z) is perpendicular to n so one has 6(x− +1) 3y+2z= 0Solving these 3 equations one finds
Trang 28c) Suppose that in the α direction ( with respect to W-E axis), at point A = (1,1,13) the hill is
steepest Evidently, dy = (tanα)dx and
b) At point A:x=y=1,z= 13 At this point, two of the tangent vectors tothe surface of thehill are
a.u/
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