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The Summing
t>l
Function
The
2 function
provides the
ability to do
a
variety
of summing
opera-
tions. The syntax
of
the function
is:
2
(
counter
variable
t
starting
aalue
t
ending
aalue z
step
size
z algebraic
expression
j
The
counter aariable takes
on a
series
of
values,
beginning
with
the
starting
ualue,
and incrementing according
to
the
step
size,
until it
passes
the
ending ualue.
For
each
value
of
the countel, the
algebraic
expression
is
evaluated,
and
the value is added to the previous
value.
The function returns the final
summation.
For
example,
when the the
equation:
SER
I
ES=E
(
I
I
I
:
6
:
1
: I xH^
I
)
is solved
for
SERIES,
it
uses
the
stored value
of X to
calculate
X
+
zxz
+
3X3
+
4X4
+
sxs
+
5X6.
The
counter
I
runs
from
1
through
5
in
steps
of L-that
is,
.'/..,2,3,
4,5,
6. For
each
value
l,
the
expression
I
x
X
^
I
is
calculated
and
added
to the
sum. The counter variable
does
not
appear
in
the menu
of
variables.
The
followi.g
equation
uses
a variable
as
the ending value, 0
as the
beginni.g
value,
and a step size
of
2.
SERIES=E(
I
:
B:
LHST:2:
IxH^I
)
If
8
is stored
in
LAST,I
takes
on
values
of
0, 2,
4,
6,
and
8.
Solving
for
SERIES
in
this
equation calculates
2X2
+
4X4
+
6X6
+
8X8.
I
08
5: The Equation
SolYer
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