# Sidens; Sigma; Sigmavx; Sign - HP 48gII Advanced User's Reference Manual

Graphing calculator.

Input/Output:

## SIDENS

Type:
Function
Description: Silicon Intrinsic Density Command: Calculates the intrinsic density of silicon as a function of
temperature, x
If x
is a unit object, it must reduce to a pure temperature, and the density is returned as a unit
T
object with units of 1/cm
If x
is a real number, its units are assumed to be K, and the density is returned as a real number
T
with implied units of 1/cm
x
must be between 0 and 1685 K.
T
...µ
Access:
Flags:
Numerical Results (-3)
Input/Output:

### SIGMA

CAS:
For given variable y, calculate discrete antiderivative G of given function f : G(y + 1) – G(y) =
f(y).

### SIGMAVX

CAS:
For current variable x, calculate discrete antiderivative G of function f : G(x + 1) – G(x) = f(x).

### SIGN

Type:
Function
Description: Sign Function: Returns the sign of a real number argument, the sign of the numerical part of a
unit object argument, or the unit vector in the direction of a complex number argument.
For real number and unit object arguments, the sign is defined as +1 for positive arguments, –1
for negative arguments. In exact mode, the sign for argument 0 is undefined (?). In approximate
mode, the sign for argument 0 is 0.
while
SIGN
For a complex argument:
Access:
...ßL
Flags:
Numerical Results (-3)
Level 2/Argument 1
Level 1/Argument 2
'symb
'
1
'symb
'
{ name
1
.
T
.
3
.
3
SIDENS
Level 1/Argument 1
x
T
x_unit
'symb'
in the
menu returns returns the unit vector of a complex number.
...ß
SIGN x
+
iy
L
REAL
SIGN
SIGN
'name'
name
... }
1
2
in the
menu returns the sign of a number,
SIGN
x
iy
=
-------------------- -
+
-------------------- -
2
2
2
2
x
+
y
x
+
y
( ´ is the left-shift of the Pkey).
( ß is the right-shift of the 1key).
Full Command and Function Reference 3-163
Level 1/Item 1
'symb
'
2
'symb
'
2
Level 1/Item 1
x
density
x_1/cm
3
'SIDENS(symb)'