Graphing Sequences - Sharp EL-9900 Operation Manual

Chapter 6: Advanced Graphing Features — Advanced Keyboard

4. Graphing Sequences

The sequence graph mode can store and simultaneously draw three graph equations
u(n), v(n), and w(n).
Variables u, v, and w are entered as @ u (or v, w).
Use X to enter the natural number n.
A sequence is an ordered set of numbers with a defined relation-
ship. The recursive sequential formulas can be described as
u = u + d
n n-1
×
u = u r
n n-1
where u is the n-th term, d is the common difference, and r is the
n
ratio. In many occasions however, the term before u
term before u ) is not known. In such cases, the explicit formulas
n
must then be derived as:
×
u = u + d
n 1
×
n-1
u = u r
n 1
where u is the n-th term, u
n
the common difference, and r is the ratio.
A sequence {2, 4, 8, 16, 32, ...} may suggest the following
recursive sequence expression:
×
n-1
u = 2 2
n
or it may also suggest the following non-recursive expression:
u = 2 n
n
The calculator can plot sequential graphs in three different
schemes, as follows:
n -based (Time)
The u values will be plotted
n
against the n value.
and/or
(n - 1) and/or
is the first term of the sequence, d is
1
(i.e., one
n-1
89