Round-off error, Round–off error – HP 35s Scientific Calculator User Manual
Page 335
D-13
Solve for X using initial guesses of 10
–8
and –10
–8
.
Round–Off Error
The limited (12–digit) precision of the calculator can cause errors due to rounding
off, which adversely affect the iterative solutions of SOLVE and integration. For
example,
has no roots because f(x) is always greater than zero. However, given initial guesses
of 1 and 2, SOLVE returns the answer 1.0000 due to round–off error.
Round–off error can also cause SOLVE to fail to find a root. The equation
has a root at
. However, no 12–digit number exactly equals
, so the
calculator can never make the function equal to zero. Furthermore, the function
never changes sign SOLVE returns the message .
Keys:
(In RPN mode)
Display:
Description:
X
_
Enters guesses.
J
Selects program "J" as the function.
X
Solves for X; displays the result.
0
10
-
]
10
1)
x
[(
30
2
15
=
+
+
0
7
-
x
2
=
7
7