Probability functions – HP 40gs User Manual

Page 166

Advertising
background image

13-12

Using mathematical functions

Example

For x

4

+2x

3

–25x

2

–26x+120:

POLYEVAL([1,2,-25,-26,120],8) returns
3432.

POLYFORM

Polynomial form. Creates a polynomial in variable1 from
expression.

POLYFORM(expression, variable1)

Example

POLYFORM((X+1)^2+1,X) returns X^2+2*X+2.

POLYROOT

Polynomial roots. Returns the roots for the nth-order
polynomial with the specified n+1 coefficients.

POLYROOT([coefficients])

Example

For x

4

+2x

3

–25x

2

–26x+120:

POLYROOT([1,2,-25,-26,120]) returns
[2,-3,4,-5].

H I N T

The results of POLYROOT will often not be easily seen in
HOME due to the number of decimal places, especially if
they are complex numbers. It is better to store the results
of POLYROOT to a matrix.

For example,

POLYROOT([1,0,0,-8]

M1 will

store the three complex cube roots of 8 to matrix M1 as
a complex vector. Then you can see them easily by going
to the Matrix Catalog. and access them individually in
calculations by referring to M1(1), M1(2) etc.

Probability functions

COMB

Number of combinations (without regard to order) of n
things taken r at a time: n!/(r!(n-r)).

COMB(n, r)

Example

COMB(5,2) returns 10. That is, there are ten
different ways that five things can be combined two
at a time.!

hp40g+.book Page 12 Friday, December 9, 2005 1:03 AM

Advertising
This manual is related to the following products: