HP 49g Graphing Calculator - Manual (Page 136)

Output:
Flags:
See also:
The derivative, or a vector of the derivatives, of the
function or functions.
Exact mode must be set (flag -105 clear).
Numeric mode must not be set (flag -03 clear).
DERIV
DESOLVE
Type: Command
Descriptiou: Solves certain first-order ordinary differential equations
with respect to the current variable.
Access: Symbolic solve,
0(SSv)
Input: Level 2/Argument 1: A first-order differential equation.
Level 1/Argument 2: The function to solve for.
Output: The solution to the equation, either
y as a
frmction of
x
or a: as a function of
y,
or
x
and
y
as fimctions of a
parameter.
Flags: Exact mode must be set (flag -105 clear).
Numeric mode must not be set (flag -03 clear).
Example: Solve the following differential equation:
y'ix)
- 1 - 2>’(x) =
Command:
D E S O L V E ( d l Y ( X ) + 2 * Y ( X ) = E X P { 3 * X ) , Y ( X ) )
Result:
{ Y ( X ) = ( 1 / 5 * E X P { 5 * X ) + C 0 * ) ( 1 / E X P ( X ) ^ ' 2 ) }
See also: LDEC
DIV
Type: Command
Description: Returns the divergence of a vector function.
Access: Calculus,
R(C a I c ) deriv . & integ .
Input: Level 2/Argument 1: An array representing a vector
fimction.
Level 1/Ai'gument 2: An array containing the variables.
Output: The divergence of the vector fimction with respect to
the specified variables.
Computer Algebra Commands Page 14-13