HP HP-15C

52
Section 2: Working With f/F]
Keystrokes Display
| ENTER |
fGSBll
| ENTER |
225| ENTER |
[ENTERj[ENTER|
2
2
2
2
.000
768
250
250
02
-85
02
02
Calculator doesn't
underflow at x = 200; try a
number between 200 and
250.
GSBI1
4.324 -96 Calculator is close to
underflow.
At this point, you can use | SOLVE] to pinpoint the smallest value of x
at which the calculator underflows.
Keystrokes
SB
Display
2.250 02
2.280 02
Roll down stack until the
last value tried is in the X-
and Y-registers.
The minimum value of x
at which the calculator
underflows is about 228.
You've now determined that you need integrate only from 0 to 228.
Since the integrand is interesting only for values of x less than 10,
divide the interval of integration there. The problem has now
become:
/
xe xdx
0
Keystrokes
7fnfpiMlf(i)1
m CLEAR rr+i
0| ENTER |
r2m /-]
^ / xe~xdx — 1
Jo JQ
Display
7.000 00
0.000 00
0.000 00
10
xe xdx
r22
Vio
xe xdx.
10 10
Allocates statistical
storage registers.
Clears statistical storage
registers.
Keys in lower limit of
integration over first
subinterval.
Keys in upper limit of
integration over first
subinterval.