Nderiv – Texas Instruments TI-84 User Manual
Page 63
Chapter 2: Math, Angle, and Test Operations
60
nDeriv(
nDeriv(
nDeriv(
nDeriv(
nDeriv(
(numerical derivative) returns an approximate derivative of
expression
with respect
to
variable
, given the
value
at which to calculate the derivative and
H (if not specified, the
default is 1
âL3).
nDeriv(
is valid only for real numbers.
nDeriv(expression,variable,value
[
,
H]
)
nDeriv(
uses the symmetric difference quotient method, which approximates the
numerical derivative value as the slope of the secant line through these points.
As
H becomes smaller, the approximation usually becomes more accurate.
You can use
nDeriv(
once in
expression
. Because of the method used to calculate
nDeriv(
,
the TI-84 Plus can return a false derivative value at a nondifferentiable point.
f
′ x
( )
f x
ε
+
(
) f x ε
–
(
)
–
2
ε
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=