Casio FX-9750GII-SC User Guide - Page 62

Differential Calculations, Using Differential Calculation in a Graph Function - derivative

Page 62 highlights

I Differential Calculations [OPTN]-[CALC]-[d/dx] To perform differential calculations, first display the function analysis menu, and then input the values using the syntax below. *(CALC)* (d/dx) f(x) a tol * fx-7400GII: (CALC) (a: point for which you want to determine the derivative, tol: tolerance) d/dx(f(x) a) d dx f(a) The differentiation for this type of calculation is defined as: f ' (a) = Alixm0-f-(-a-+-A-A-xx)----f-(-a-) In this definition, infinitesimal is replaced by a sufficiently small x, with the value in the neighborhood of f' (a) calculated as: f (a + Ax) - f (a) f' (a) ------A-x------ In order to provide the best precision possible, this unit employs central difference to perform differential calculations. Example To determine the derivative at point x = 3 for the function y = x3 + 4x2 + x - 6, with a tolerance of "tol" = 1E - 5 Input the function f(x). *(CALC)* (d/dx)T,B CTV T E * fx-7400GII: (CALC) Input point x = a for which you want to determine the derivative. B Input the tolerance value. @$ DU Using Differential Calculation in a Graph Function • Omitting the tolerance (tol) value when using the differential command inside of a graph function simplifies the calculation for drawing the graph. In such a case, precision is sacrificed for the sake of faster drawing. The tolerance value is specified, 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. Differential Calculation Precautions • In the function f(x), only X can be used as a variable in expressions. Other variables (A through Z excluding X, r, Ƨ) are treated as constants, and the value currently assigned to that variable is applied during the calculation. • Input of the tolerance (tol) value and the closing parenthesis can be omitted. If you omit tolerance (tol) value, the calculator automatically uses a value for tol as 1E-10. • Specify a tolerance (tol) value of 1E-14 or greater. An error (Time Out) occurs whenever no solution that satisfies the tolerance value can be obtained. • Pressing during calculation of a differential (while the cursor is not shown on the display) interrupts the calculation. 2-24

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2-24
Differential Calculations
[OPTN]
-
[CALC]
-
[
d
/
dx
]
To perform differential calculations, first display the function analysis menu, and then input the
values using the syntax below.
(CALC)*
(
d
/
dx
)
f
(
x
)
a
tol
* fx-7400G
II
:
(CALC)
(
a
: point for which you want to determine the derivative,
tol
: tolerance)
The differentiation for this type of calculation is defined as:
In this definition,
infinitesimal
is replaced by a
sufficiently small
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.
Example
To determine the derivative at point
x
= 3 for the function
y
=
x
3
+4
x
2
+
x
– 6, with a tolerance of “
tol
”=1
E
–5
Input the function
f
(
x
).
(CALC)*
(
d
/
dx
)
* fx-7400G
II
:
(CALC)
Input point
x
=
a
for which you want to determine the derivative.
Input the tolerance value.
Using Differential Calculation in a Graph Function
• Omitting the tolerance (
tol
) value when using the differential command inside of a graph
function simplifies the calculation for drawing the graph. In such a case, precision is
sacrificed for the sake of faster drawing.The tolerance value is specified, 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.
Differential Calculation Precautions
• In the function
f
(
x
), only X can be used as a variable in expressions. Other variables
(A through Z excluding X,
r
,
) are treated as constants, and the value currently assigned to
that variable is applied during the calculation.
• Input of the tolerance (
tol
) value and the closing parenthesis can be omitted. If you omit
tolerance (
tol
) value, the calculator automatically uses a value for
tol
as 1
E
–10.
• Specify a tolerance (
tol
) value of 1
E
–14 or greater. An error (Time Out) occurs whenever no
solution that satisfies the tolerance value can be obtained.
• Pressing
during calculation of a differential (while the cursor is not shown on the display)
interrupts the calculation.
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
'