Texas Instruments TI-89 Titanium - Page 222

216 Appendix A: Functions and Instructions
P4Rx() MATH/Angle menu
P4Rx( rExpression , q Expression ) ⇒ expression
P4Rx( rList , q List ) ⇒ list
P4Rx( rMatrix , q Matrix ) ⇒ matrix
Returns the equivalent x-coordinate of the
(r, q) pair.
Note: The q argument is interpreted as either a
degree or radian angle, according to the current
angle mode. If the argument is an expression, you
can use ó or ô to override the angle mode setting
temporarily.
In Radian angle mode:
P4Rx(r,q) ¸ cos(q)ø r
P4Rx(4,60¡)
¸ 2
P4Rx({ë 3,10,1.3},{p/3,ë p/4,0})
¸
{
ë 3/2 5ø ‡2 1.3
}
P4Ry() MATH/Angle menu
P4Ry( rExpression , q Expression ) ⇒ expression
P4Ry( rList , q List ) ⇒ list
P4Ry( rMatrix , q Matrix ) ⇒ matrix
Returns the equivalent y-coordinate of the
(r, q) pair.
Note: The q argument is interpreted as either a
degree or radian angle, according to the current
angle mode. If the argument is an expression, you
can use ó or ô to override the angle mode setting
temporarily.
In Radian angle mode:
P4Ry(r,q) ¸ sin(q)ø r
P4Ry(4,60¡)
¸
2ø ‡3
P4Ry({ë 3,10,1.3},{p/3,ë p/4,0})
¸
{
ë 3ø ‡3
2
ë 5ø
‡2
0.
}
part() CATALOG
part( expression1 [ , nonNegativeInteger ])
This advanced programming function lets you
identify and extract all of the sub-expressions in
the simplified result of
expression1 .
For example, if
expression1 simplifies to
cos(pù x+3):
• The
cos() function has one argument:
(pù x+3).
• The sum of (pù x+3) has two operands: pù x
and 3.
• The number 3 has no arguments or operands.
• The product pù x has two operands: p and x.
• The variable x and the symbolic constant p
have no arguments or operands.
If x has a numeric value and you press
¥¸,
the numeric value of pù x is calculated, the result
is added to 3, and then the cosine is calculated.
cos() is the top-level operator because it is
applied last.
part( expression1 ) ⇒ number
Simplifies expression1 and returns the number of
top-level arguments or operands. This returns 0 if
expression1 is a number, variable, or symbolic
constant such as p,
e , i , or ˆ.
part(cos(pù x+3)) ¸ 1
Note: cos(pù x+3) has one argument.
part( expression1 , 0) ⇒ string
Simplifies expression1 and returns a string that
contains the top-level function name or operator.
This returns
string( expression1 ) if expression1 is a
number, variable, or symbolic constant such as p,
e , i , or ˆ.
part(cos(pù x+3),0) ¸ "cos"