Texas Instruments TI-86 - Manual (Page 335)

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 118 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 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(valueNd)) 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 L4:
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