HP 40gs - Manual (Page 165)

Using mathematical functions 13-11
RECURSE 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
n
, term
1
, term
2
)
Example
RECURSE(U,U(N-1)*N,1,2) U1(N)
Stores a factorial-calculating function named U1.
When you enter U1(5), for example, the function
calculates 5! (120).
Σ Summation. Finds the sum of expression with respect to
variable from initialvalue to finalvalue.
Σ(variable=initialvalue, finalvalue, expression)
Example
Σ(C=1,5,C 2
) returns 55.
Matrix functions
These functions are for matrix data stored in matrix
variables. See “Matrix functions and commands” on
page 18-10.
Polynomial functions
Polynomials are products of constants (coefficients) and
variables raised to powers (terms).
POLYCOEF 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
4 +2x 3 –25x 2 –26x+120.
POLYEVAL Polynomial evaluation. Evaluates a polynomial with the
specified coefficients for the value of
x.
POLYEVAL([coefficients], value)
hp40g+.book Page 11 Friday, December 9, 2005 1:03 AM