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Chapter 20: A to Z Function and Instruction Reference
323
20ATOZ.DOC TI-86, Chap 20, US English Bob Fedorisko Revised: 02/13/01 2:42 PM Printed: 02/13/01 3:05 PM Page 323 of 11820ATOZ.DOC TI-86, Chap 20, US English Bob Fedorisko Revised: 02/13/01 2:42 PM Printed: 02/13/01 3:05 PM Page 323 of 118
nDer(
CALC menu
To view or set the value for
d
, press
-
™
)
to
display the tolerance
screen.
nDer(
expression
,
variable
,
value
)
Returns an approximate numerical derivative of
expression
with respect to
variable
evaluated at a real
or complex
value
. The approximate numerical
derivative is the slope of the secant line through the
points:
(
value
Nd
,f(
value
Nd
)) and (
value+
d
,f(
value
+
d
))
As the step value
d
gets smaller, the approximation
usually gets more accurate.
For
d
=.001:
nDer(x^3,x,5)
b
75.000001
For
d
=1
E
L
4:
nDer(x^3,x,5)
b
75
nDer(
expression
,
variable
)
Uses the current value of
variable
.
5
x
b
5
nDer(x^3,x)
b
75
Negation:
L
a
L
number
or
L
(
expression
)
L
list
L
matrix
L
vector
Returns the negative of the real or complex argument.
L
2+5
b
3
L
(2+5)
b
L
7
L
{0,
L
5,5}
b
{0 5
L
5}
norm
MATRX MATH menu
VECTR MATH menu
norm
matrix
Returns the Frobenius norm of a real or complex
matrix
, calculated as:
G
(
real
2
+
imaginary
2
)
where the sum is over all elements.
[[1,
L
2][
L
3,4]]
MAT
b
[[1
L
2]
[
L
3 4 ]]
norm MAT
b
5.47722557505