HP 39gs Master Manual page 301

Step4. Because I know that part (iv) of the question requires me to re­
use these extremum values in an integration (which I would like
to be as accurate as possible), I am going to 'save' the
extremum value just found. I change into the
store it as shown in memory
Note: You MUST store the point of interest before moving the
cursor in the
PLOT
position over-writes the extremum value. If you want the y
coordinate, just evaluate
Now use the
x coordinate of the second turning point into memory
shown.
Step 5. The view shows that part of the area we require for part
PLOT
(iv) is negative, so we need to know the x intercept between
the two turning points. Fortunately we know from Step 2 that it
is the point (2,0). If we did not know this already, then we
could use the
menu the variable called '
VAR
into memory
C
We will evaluate the integral in the
can use the accurate values you stored in Step 4. It needs to
be done in two parts and added (subtracted actually to reverse
the sign of the negative part). This is shown right, with the
key having been used to add the values.
.
A
view. As soon as the cursor moves its new
.
F(X)
Extremum tool again to find and store the
menu again, retrieving this time from the
' and perhaps storing that
Root
.
HOME
view and
HOME
as
B
view where you
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