Texas Instruments TI-83 - Page 123

Sequence Graphing 6-5
8306SEQN.DOC TI-83 international English Bob Fedorisko Revised: 02/19/01 12:22 PM Printed: 02/19/01 1:36
PM Page 5 of 16
To define or edit a sequence function, follow the steps in
Chapter 3 for defining a function. The independent variable
in a sequence is
n .
In
Seq graphing mode, you can enter the sequence variable
in either of two ways.
•
Press
„
.
•
Press
y
[
CATALOG
] [
N
].
You can enter the function name from the keyboard.
•
To enter the function name
u, press
y
[
u
] (above
¬
).
•
To enter the function name
v, press
y
[
v
] (above
−
).
•
To enter the function name
w, press
y
[
w
] (above
®
).
Generally, sequences are either nonrecursive or recursive.
Sequences are evaluated only at consecutive integer
values.
n is always a series of consecutive integers, starting
at zero or any positive integer.
In a nonrecursive sequence, the
n th term is a function of
the independent variable
n . Each term is independent of all
other terms.
For example, in the nonrecursive sequence below, you can
calculate
u(5) directly, without first calculating u(1) or any
previous term.
The sequence equation above returns the sequence
2, 4, 6, 8, 10, . . . for n = 1, 2, 3, 4, 5,
. . . .
Note:
You may leave blank the initial value
u(nMin)
when calculating
nonrecursive sequences.
Defining and
Editing a
Sequence
Function
Nonrecursive
Sequences