Casio FX-CG10 User Manual
Page 74
2-28
In this definition, infinitesimal is replaced by a sufficiently small
A
x
, with the value in the
neighborhood of
f
'
(
a
) calculated as:
Example
To determine the derivative at
x
= 3 for the function
y
=
x
3
+ 4
x
2
+
x
– 6
Input the function
f
(
x
).
AK4(CALC) 2( d / d
x
)
vMde+evx+v-ge
Input point
x
=
a
for which you want to determine the derivative.
d
w
Using First Derivative Calculation in a Graph Function
• You can omit input of the value
a
in the syntax on page 2-27 by using the following format
for the first derivative graph: Y2 = d / d
x
(Y1). In this case, the value of the X variable is used
instead of the value
a
.
First Derivative 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.
• Pressing
A during calculation of a first derivative (while the cursor is not shown on the
display) interrupts the calculation.
• Inaccurate results and errors can be caused by the following:
- discontinuous points in
x
values
- extreme changes in
x
values
- inclusion of the local maximum point and local minimum point in
x
values
- inclusion of the inflection point in
x
values
- inclusion of undifferentiable points in
x
values
- first derivative calculation results approaching zero
• Always use radians (Rad mode) as the angle unit when performing trigonometric first
derivatives.
• You cannot use a first derivative, second derivative, integration,
Σ , maximum/minimum value,
Solve or RndFix calculation expression inside a first derivative calculation term.
f (a +
Ax) – f (a)
f (a) –––––––––––––
Ax
'
f (a +
Ax) – f (a)
f (a) –––––––––––––
Ax
'