HP 40gs User Manual page 297

hp40g+.book Page 23 Friday, December 9, 2005 1:03 AM
Step-by-Step Examples
Solution 1
Start by defining G(X):
DEF G
X
= 2 X
3
X 2
Now press :
Press and to select
the numerator and
denominator, and then
press . This
leaves G(X) displayed:
Finally, apply the TABVAR
function:
TABVAR
and press a
number of times until
the variation table appears (shown above).
The first line of the variation table gives the sign of
g' x ( )
according to x, and the second line the variations
of g (x). Note that for TABVAR the function is always
called F.
We can deduce, then, that g(x) increases over [0, 2].
If you had been in step-by-step mode, you would have
obtained:
⋅
2 X + 3
------------------- -
F =
X + 2
Pr
ess to get the
result at the right.
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