HP 40gs, User Manual

Page: 166 / 444

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 n th-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