Casio fx-9750G Differential/Quadratic Differential, Integration, Value User Manual
Page 6
68
This average, which is called the
central difference, is expressed as:
uuuuu
To perform a differential calculation
Example
To determine the derivative at point
x
=
3 for the function
y
=
x
3
+
4
x
2
+
x
–
6, when the increase/decrease of
x
is defined as
∆
x
=
1
E
–
5
Input the function
f(x)
.
A
K4
(CALC)
2
(
d/dx
)
v
Md+evx
+v-g,
Input point
x
=
a
for which you want to determine the derivative.
d,
Input
∆
x
, which is the increase/decrease of
x
.
bE-f)
w
• In the function
f(x)
, only X can be used as a variable in expressions. Other vari-
ables (A through Z,
r
,
θ
) are treated as constants, and the value currently as-
signed to that variable is applied during the calculation.
• Input of
∆
x
and the closing parenthesis can be omitted. If you omit
∆
x
, the calcu-
lator automatically uses a value for
∆
x
that is appropriate for the derivative value
you are trying to determine.
• Discontinuous points or sections with drastic fluctuation can adversely affect pre-
cision or even cause an error.
1
f (a +
∆
x) – f (a)
f (a) – f (a –
∆
x)
f '(a) =
–– –––––––––––––
+
–––––––––––––
2
∆
x
∆
x
f (a +
∆
x) – f (a –
∆
x)
=
–––––––––––––––––
2
∆
x
3 - 3
Differential Calculations