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As they do,
marks appear on all three, but
ing or un-
ing
any one does the same for all three.
Convenient screen keys provided
There are a number of very convenient extra buttons provided at the bottom
of the screen when entering sequences.
Two of these -
and
- are
available as soon as the cursor moves onto
the
U(N)
line (see right). Pressing either will
enter the appropriate text into the sequence
definition.
The rest become visible once you have begun
to enter the sequence definition.
For example, suppose we enter the Fibonacci sequence into U2 by defining
U2(N)
as
U2(N-1)
+
U2(N-2)
. Rather than having to type all of this we
can use the buttons provided, pressing:
then
then
+
then
then
This is a very convenient feature, and worth remembering. The result…
There is no
mark next to the definition
yet, since the sequence is defined recursively
and no values have yet been given for
U2(1)
and
U2(2)
. Type in a value of
1
for both of
these and then press the
NUM
button to switch
to the
NUM
view.
As you can see in the screenshot right, the
NUM
view shows the actual values in the
sequence as a table. If you move the highlight
into the
U1
and
U2
columns, you can press the
button and see the sequence rule. You
can experiment for yourself and see the result
of pressing the
button (see next page for an example). The
button is also available as usual, but it is easier to use other methods.
