HP 50G, Руководство пользователя

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Page 9-2
where
θ
is the angle between the two vectors. The cross product produces a
vector A
×
B whose magnitude is | A
×
B | = | A || B |sin(
θ
), and its direction is
given by the so-called right-hand rule (consult a textbook on Math, Physics, or
Mechanics to see this operation illustrated graphically). In terms of Cartesian
components,
A
•
B = A
x
B
x
+A
y
B
y
+A
z
B
z
, and A
×
B = [A
y
B
z
-A
z
B
y
,A
z
B
x
-A
x
B
z
,A
x
B
y
-
A
y
B
x
]. The angle between two vectors can be found from the definition of the
dot product as cos(
θ
) = A
•
B /| A || B |= e
A
•
e
B
. Thus, if two vectors A and B
are perpendicular (
θ
= 90
0
=
π
/2
rad
), A
•
B = 0.
Entering vectors
In the calculator, vectors are represented by a sequence of numbers enclosed
between brackets, and typically entered as row vectors. The brackets are
generated in the calculator by the keystroke combination
„Ô
, associated
with the
*
key. The following are examples of vectors in the calculator:
[3.5, 2.2, -1.3, 5.6, 2.3]
A general row vector
[1.5,-2.2]
A 2-D vector
[3,-1,2]
A 3-D vector
['t','t^2','SIN(t)']
A vector of algebraics
Typing vectors in the stack
With the calculator in ALG mode, a vector is typed into the stack by opening a
set of brackets (
„Ô
) and typing the components or elements of the vector
separated by commas (
‚í
). The screen shots below show the entering of
a numerical vector followed by an algebraic vector. The figure to the left shows
the algebraic vector before pressing
„
. The figure to the right shows the
calculator’s screen after entering the algebraic vector:
In RPN mode, you can enter a vector in the stack by opening a set of brackets
and typing the vector components or elements separated by either commas
(
‚í
) or spaces (
#
). Notice that after pressing
`
, in either mode,
the calculator shows the vector elements separated by spaces.