The 'Polynomial' Group Of Functions - HP 39gs Master Manual

T h e ' P o l y n o m i a
T h e ' P o l y n o m i a
This group of functions is provided to manipulate polynomials.
We will use the function shown right to illustrate some of the tools in
the Polynomial group. Its equation is:
( ) = − 2)(x + 3)(x −1) =
f x (x
POLYCOEF([root1,root2,...])
This function returns the coefficients of a polynomial with roots x x x
vector form means in square brackets.
The function f x above has roots 2, -3 and 1. The screen shot below shows
( )
the coefficients as 1, 0, -7 and 6 for a final polynomial of f x
POLYEVAL([coeff1,coeff2,...],value)
This function evaluates a polynomial with specified coefficients at the
point specified. The coefficients must be in square brackets, followed by
the value of x (not in brackets). ie. f x =
at x = 3.
Note: This is a function that is aimed more at programmers. For normal users it is probably more efficient to
enter the function into the
the function values required, or simply type
l ' g r o u p o f f u n c
l ' g r o u p o f f u n c
− + 6
3
x 7x
( )
−
3
x 7 x
view of the Function aplet and then either use the
SYMB
t i o n s
t i o n s
,... The roots must be supplied in
, ,
1 2 3
( ) = x −
3
7x
+ 6 has value 12
, etc. in the
F1(3) F1(-2)
202
f(x)
14
12
10
8
6
4
2
-5 -4 -3 -2 -1 1
-2
-4
correctly giving
POLYCOEF
+ 6 .
NUM
view.
HOME
x
2 3 4 5
view to find