Casio fx-115ES - Manual (Page 37)

E-35
Tips on Improving Integration Value Accuracy
• When a periodic function or integration interval results in positive
and negative f ( x ) function values
Perform separate integrations for each cycle, or for the positive
part and the negative part, and then combine the results.
Positive Part Negative Part
( S Positive) ( S Negative)
• When integration values fluctuate widely due to minute shifts in
the integration interval
Divide the integration interval into multiple parts (in a way that
breaks areas of wide fluctuation into small parts), perform
integration on each part, and then combine the results.
Appendix
<#031>
∫
(ln( x ), 1, e ) = 1 ( tol specification omitted.)
<#032>
∫ (
, 1, 5, 1 ×10 –7
)
= 0.8
a
b
f(x)dx =
a
x
1
f(x)dx +
x
1
x
2
f(x)dx + .....+
x
4
b
f(x)dx
∫ ∫ ∫ ∫
∫ ∫ ∫
a
b
f(x)dx =
a
c
f(x)dx + (–
c
b
f(x)dx)
1
x 2
S Negative
S Positive