Operation Manual
1-20 Operating the TI
.
82
8201OPER.DOC TI-82, Chapter 1, English Bob Fedorisko Revised: 02/09/01 12:18 PM Printed:
02/09/01 12:35 PM Page 20 of 22
EOS™ (Equation Operating System)
The Equation Operating System (EOS
é
) defines the order in which functions in
expressions are entered and evaluated on the TI
.
82. EOS lets you enter numbers
and functions in a simple, straightforward sequence.
Order of Evaluation
A function returns a value. EOS evaluates the functions in an expression in
the following order:
1
Functions that are entered after the argument, such as
2
,
-1
,
!
,
¡
,
r
,
T
, and conversions.
2
Powers and roots, such as
2^5
or
5
x
‡
32
.
3
Implied multiplication where the second argument is a number,
v
ariable name, list, or matrix or begins with an open parenthesis,
such as
4A
,
3
ã
B
ä
,
(A+B)4
, or
4(A+B)
.
4
Single-argument functions that precede the argument, such as
negation,
‡
,
sin
, or
log
.
5
Implied multiplication where the second argument is a
multiargument function or a single-argument function that
precedes the argument, such as
2nDeriv(A
2
,A,6)
or
Asin 2
.
6
Permutations (
nPr
) and combinations (
nCr
).
7
Multiplication and division.
8
Addition and subtraction.
9
Relational functions, such as
>
or
.
10
Logic operator
and
.
11
Logic operators
or
and
xor
.
Within a priority group, EOS evaluates functions from left to right.
However, two or more single-argument functions that precede the same
argument are evaluated from right to left. For example,
sin fPart ln 8
is
evaluated as
sin(fPart(ln 8))
.
Calculations within a pair of parentheses are evaluated first. Multiargument
functions, such as
nDeriv(A
2
,A,6)
, are evaluated as they are encountered.