HP (Hewlett-Packard) 40gs Calculator User Manual


 
14-66 Computer Algebra System (CAS)
ILAP is the inverse Laplace transform of a given
expression. Again, the expression is the value of a
function of the variable stored in VX.
Laplace transform (LAP) and inverse Laplace transform
(ILAP) are useful in solving linear differential equations
with constant coefficients, for example:
The following relations hold:
where c is a closed contour enclosing the poles of f.
The following property is used:
The solution, y, of:
is then:
Example
To solve:
c
type:
LAP(X · EXP(3 · X))
The result is:
y py qy++ fx()=
y 0() a y 0() b==
LAP(y)(x) e
x t
yt()td
0
+
=
ILAP(f)(x)
1
2iπ
--------
e
zx
fz()zd
c
=
L
AP y()x() y 0() x LAP y()x()+=
y py qy++ fx(), y 0() a, y 0() b===
ILAP
LAP fx()()xp+()ab++
x
2
px q++
-------------------------------------------------------------------
⎝⎠
⎛⎞
y 6 y 9 y+ xe
3x
, y 0() a, y 0() b===
1
x
2
6x–9+
--------------------------
hp40g+.book Page 66 Friday, December 9, 2005 1:03 AM