HP hp39gPlus User Guide - Page 155

Polyeval, Polyform, Polyroot

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POLYEVAL Polynomial evaluation. Evaluates a polynomial with the specified coefficients for the value of x. POLYEVAL([coefficients], value) Example For x4+2x3-25x2-26x+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 HINT Polynomial roots. Returns the roots for the nth-order polynomial with the specified n+1 coefficients. POLYROOT([coefficients]) Example For x4+2x3-25x2-26x+120: POLYROOT([1,2,-25,-26,120]) returns [2,-3,4,-5]. 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. Using mathematical functions 11-11

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Using mathematical functions
11-11
POLYEVAL
Polynomial evaluation. Evaluates a polynomial with the
specified
coefficients
for the
value
of
x
.
POLYEVAL([
coefficients
]
,
value
)
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]
.
HINT
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.