HP HP-15C

54 Section 2: Working With [W\s Display
[TsTl 5.328 -04
RCL 2 +
2.000
1.000
00
00
2.598 -04
Returns approximation
and its uncertainty to the
X- and Y-registers,
respectively, before
summing them in
statistical storage
registers.
Sums approximation and
its uncertainty.
Integral over total
interval (0, 228) (recalled
from R3).
Uncertainty of integral
(from R5),
Transformation of Variables
In many problems where the function changes very slowly over
most of a very wide interval of integration, a suitable transfor-
mation of variables may decrease the time required to calculate the
integral.
For example, consider again the integral
I xe xdx .
e~x - u3.
x = -3 In u
du
dx = -3 .
u
Let
Then
and
Substituting,
f°
=J 9u2ln
(-3 In
udu
Key in a subroutine that evaluates the function /(w) = 9u2ln u.