# Matrix Functions; Polynomial Functions - HP 40gs User Manual

Graphing calculator.

RECURSE
Σ

## Matrix functions

### Polynomial functions

POLYCOEF
POLYEVAL
Using mathematical functions
Provides a method of defining a sequence without using
the Symbolic view of the Sequence aplet. If used with |
("where"), RECURSE will step through the evaluation.
RECURSE(sequencename, term
Example
RECURSE(U,U(N-1)*N,1,2)
Stores a factorial-calculating function named U1.
When you enter U1(5), for example, the function
calculates 5! (120).
Summation. Finds the sum of expression with respect to
variable from initialvalue to finalvalue.
Σ(variable=initialvalue, finalvalue, expression)
Example
2
Σ(C=1,5,C
) returns 55.
These functions are for matrix data stored in matrix
variables. See "Matrix functions and commands" on
page 18-10.
Polynomials are products of constants (coefficients) and
variables raised to powers (terms).
Polynomial coefficients. Returns the coefficients of the
polynomial with the specified roots.
POLYCOEF ([roots])
Example
To find the polynomial with roots 2, –3, 4, –5:
POLYCOEF([2,-3,4,-5]) returns[1,2,-25,
-26,120], representing x
Polynomial evaluation. Evaluates a polynomial with the
specified coefficients for the value of x.
POLYEVAL([coefficients], value)
, term
, term
n
1
U1(N)
4
3
2
+2x
–25x
–26x+120.
)
2
13-11