Differential Calculations; Using Differential Calculation In A Graph Function - Casio fx-9860G Series User Manual

k Differential Calculations
To perform differential calculations, fi rst display the function analysis menu, and then input
the values using the syntax below.
4(CALC)2(
d/dx ( f (x) a) ⇒ d/dx ( f (x) a) ⇒
The differentiation for this type of calculation is defi ned as:
f '(a) = lim –––––––––– ––– f '(a) = lim –––––––––– –––
x →0 x →0
In this defi nition, infi nitesimal is replaced by a suffi ciently small
neighborhood of f
f (a + x) – f (a) f (a + x) – f (a)
f '(a) f '(a) –––––––––– ––– –––––––––– –––
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.
Numerical Calculations
d dx f x a
/ ) ( ),
d d
f (a) f (a)
dx dx
f (a + x) – f (a) f (a + x) – f (a)
x x
'
( a) calculated as:
x x
2-5-2
tol
, )
a
( : point for which you want to determine the
derivative, tol: tolerance)
20070201
[OPTN]-[CALC]-[
x
, with the value in the
d dx
/ ]