Texas Instruments TI-89 - Index_If_Pushed_Qquad_Info

240
Appendix A: System Routines — Algebra Utilities
TI
-
89 / TI
-
92 Plus Developer Guide
Not for Distribution
Beta Version January 26, 2001
index_if_pushed_qquad_info
Declaration:
EStackIndex
index_if_pushed_qquad_info
(EStackIndex
i
,
EStackIndex
x
, EStackIndex
h
)
Category(ies):
Algebra Utilities
Description:
a
†
x^(2h)
+ b
†
x^h
+ c is quasi-quadratic in
x
, with half-degree
h
.
h
indexes a number,
x
indexes a variable, and
i
indexes a polynomial in
that variable — generalized to allow non-negative fractional powers.
Determines whether or not the polynomial is a quasi-quadratic of
half-degree
h
in
x
. If you do not know
h
, first use
push_poly_deg_in_var_or_kernel
( . . . ).
For example: If
i
indexes u^3
†
(v^6 + v^3
†
w) + u + 1 and
x
indexes v and
h
indexes 3, then pushes u + 1, then u^3
†
w, then u^3, then returns the
index of the pushed u^3
†
w.
Inputs:
i
— Index of the top tag of an internally-simplified algebraic expression.
x—
Index of the top tag of a variable.
h
— Index of the top tag of a tagged number.
Outputs:
Returns NULL_INDEX if the polynomial is not quasi-quadratic of
half-degree
h
in
x
. Otherwise pushes onto the estack the constant, then
middle, then lead coefficient; then returns the index of the middle
coefficient.
Assumptions:
None
Side Effects:
None
Availability:
All versions of the TI
-
89 / TI
-
92 Plus.
TI
-
89 / TI
-
92 Plus
Differences:
None
See Also: push_poly_deg_in_var_or_kernel, linear_degree, did_push_lincf,
index_if_pushed_binomial_info
(continued)