HP 40gs User Manual
Page 209

Computer Algebra System (CAS)
14-27
TABVAR
Variation table
TABVAR has as a parameter an expression with a
rational derivative.
TABVAR returns the variation table for the expression in
terms of the current variable.
Typing:
TABVAR(3X
2
-8X-11)
gives, in step-by-step mode:
Variation table:
The arrows indicate whether the function is increasing or
decreasing during the specified interval. This particular
variation table indicates that the function F(x) decreases
for x in the interval [–∞, ], reaching a minimum of
at x = . It then increases in the interval [ , +∞], reaching
a maximum of +∞.
Note that “?” appearing in the variation table indicates
that the function is not defined in the corresponding
interval.
TAYLOR0
Limited expansion in the vicinity of 0
TAYLOR0 has a single argument: the function of x to
expand. It returns the function’s limited 4th-relative-order
expansion in the vicinity of x=0 (if x is the current
variable).
1
16
------ h
4
⋅
1
–
8
------ h
3
⋅
1
2
--- h
2
⋅
h
+
+
+
0 h
5
( )
+
h
x
=
(
)
–
∞
–
+
+
∞
X
+
∞
↓
↑
+
∞
F
F
3 x
2
⋅
8 x
⋅
–
11
–
(
)
=
F'
3 2 x 8
–
⋅ ⋅
(
)
=
2
3 x 4
–
⋅
(
)
⋅
(
)
→
4
3
---
49
–
3
----------
4
3
---
49
–
3
----------
4
3
---
4
3
---
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