20070201
k Differential Calculations [OPTN] - [CALC] - [ d / dx ]
To perform differential calculations, fi rst display the function analysis menu, and then input
the values using the syntax below.
K 4 (CALC)2 ( d / dx ) f ( x ), a , tol )
(
a : point for which you want to determine the
derivative, tol : tolerance)
The differentiation for this type of calculation is defi ned as:
In this defi nition, infi nitesimal is replaced by a s uffi ciently small A
x , with the value in the
neighborhood of f
'
( a ) calculated as:
In order to provide the best precision possible, this unit employs central difference to perform
differential calculations.
Using Differential Calculation in a Graph Function
• Omitting the tolerance ( tol ) value when using the differential command inside of a graph
function simplifi es the calculation for drawing the graph. In such a case, precision is
sacrifi ced for the sake of faster drawing. The tolerance value is specifi ed, the graph
is drawn with the same precision obtained when you normally perform a differential
calculation.
• You can also omit input of the derivative point by using the following format for the
differential graph: Y2= d / dx (Y1). In this case, the value of the X variable is used as the
derivative point.
d
/
dx
(
f
(
x
)
a
)
⇒
f
(
a
)
dx
d
d
/
dx
(
f
(
x
)
a
)
⇒
f
(
a
)
dx
d
f
(
a
+
A
x
)–
f
(
a
)
f
'(
a
) = lim
–––––––––––––
A
x
A
x
→
0
f
(
a
+
A
x
)–
f
(
a
)
f
'(
a
) = lim
–––––––––––––
A
x
A
x
→
0
f
(
a
+
A
x
)–
f
(
a
)
f
'(
a
)
–––––––––––––
A
x
f
(
a
+
A
x
)–
f
(
a
)
f
'(
a
)
–––––––––––––
A
x
2-5-2
Numerical Calculations
