Mrowadd(), Ncr(), Nderiv() – Texas Instruments PLUS TI-89 User Manual

Page 487

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470 Appendix A: Functions and Instructions

8992APPA.DOC TI-89 / TI-92 Plus: Appendix A (US English) Susan Gullord Revised: 02/23/01 1:48 PM Printed: 02/23/01 2:21 PM Page 470 of 132

mRowAdd()

MATH/Matrix/Row ops menu

mRowAdd(

expression

,

matrix1

,

index1

,

index2

)

matrix

Returns a copy of

matrix1

with each element

in row

index2

of

matrix1

replaced with:

expression

× row

index1

+ row

index2

mRowAdd(ë 3,[1,2;3,4],1,2) ¸

[

1 2

0

L2

]

mRowAdd(n,[a,b;c,d],1,2) ¸

[

a

aø n+c

b

bø n+d

]

nCr()

MATH/Probability menu

nCr(

expression1

,

expression2

)

expression

For integer

expression1

and

expression2

with

expression1

expression2

‚ 0,

nCr()

is the

number of combinations of

expression1

things

taken

expression2

at a time. (This is also

known as a binomial coefficient.) Both
arguments can be integers or symbolic
expressions.

nCr(

expression, 0

)

1

nCr(

expression, negInteger

)

0

nCr(

expression, posInteger

)

expressionø (expressionì 1)...

(expressionì posInteger+1)/ posInteger!

nCr(

expression, nonInteger

)

expression!/

((expressionì nonInteger)!ø nonInteger!)

nCr(z,3)

zø (zм 2)ш (zм 1)

6

ans(1)|z=5

10

nCr(z,c)

z!

c!(zì c)!

ans(1)/nPr(z,c)

1

c!

nCr(

list1

,

list2

)

list

Returns a list of combinations based on the
corresponding element pairs in the two lists.
The arguments must be the same size list.

nCr({5,4,3},{2,4,2}) ¸

{10 1 3}

nCr(

matrix1

,

matrix2

)

matrix

Returns a matrix of combinations based on
the corresponding element pairs in the two
matrices. The arguments must be the same
size matrix.

nCr([6,5;4,3],[2,2;2,2]) ¸

[

15 10
6 3

]

nDeriv()

MATH/Calculus menu

nDeriv(

expression1

,

var[

,

h]

)

expression

nDeriv(

expression1

,

var, list

)

list

nDeriv(

list

,

var[

,

h]

)

list

nDeriv(

matrix

,

var[

,

h]

)

matrix

Returns the numerical derivative as an
expression. Uses the central difference
quotient formula.

h

is the step value. If

h

is omitted, it defaults

to 0.001.

When using list or matrix, the operation gets
mapped across the values in the list or across
the matrix elements.

Note:

See also

avgRC()

and d

()

.

nDeriv(cos(x),x,h) ¸

ë (cos(xì h)ì cos(x+h))

2ø h

limit(nDeriv(cos(x),x,h),h,0)
¸

ë sin(x)

nDeriv(x^3,x,0.01) ¸

3.ø (xñ +.000033)

nDeriv(cos(x),x)|x=

p/2 ¸

ë 1.

nDeriv(x^2,x,{.01,.1}) ¸

{ 2 . ø x 2 . ø x }

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