HP 39gs Master Manual page 343

There are two ways that functions can be used in the CAS. The first is to use them as the expression is entered.
In this method the order is to choose the function and then to fill in the parameters required. The second is to
apply a function to all or part of an expression that has perhaps resulted from a previous calculation or been
typed in first. If you highlight an expression and then choose a function the expression will appear as the first
parameter in the function. A list of the functions in their various menus is given on page 358.
Example 3: Using lim
x − 2 x − 35
2
i) Find
lim
x − 7
x → 7
The sequence of keys for this is...
scroll to and press
lim
- 2
- 7
1
ii) Find
lim
x − 2
−
x→ 2
The sequence of keys for this is...
scroll to then
lim
scroll to
MATH
SHIFT ENTER ENTER
Some notes:
1. The limit approached from above would be
entered as
QUOTE(2 + 0)
2. The use of the
QUOTE
an algebraic entity rather than immediately evaluating it as simply "2". Thus the result of
3. The two functions
LIMIT
but was added on the 40gs. Because it was a late entry it appears one way in some menus and as
lim
the alternative in the others. Functionally there is no difference so why it was added is not clear.
.
ENTER
- 35
7 ENTER
.
ENTER 1
QUOTE ENTER 2 - 0
.
function forces the CAS to treat the "
and are the same. On the old model hp 40g the only function was
lim
- 2
" as
2 - 0
343
−∞
.
LIMIT