HP 40gs, User Manual, Page: 206 / 444

14-24 Computer Algebra System (CAS)
PREVAL is used for calculating an integral defined from a
primitive: it evaluates this primitive between the two limits
of the integral.
Typing:
PREVAL(X
2
+X,2,3)
gives:
6
RISCH
Primitive and defined integral
RISCH has two parameters: an expression and the name
of a variable.
RISCH returns a primitive of the first parameter with
respect to the variable specified in the second parameter.
Typing:
RISCH((2·X
2
+1)·EXP(X
2
+1),X)
gives:
X·EXP(X
2
+1)
N O T E : If the RISCH parameter is the AND of two elements,
RISCH concerns itself only with the second element of the
AND, and adds the result to the first argument.
SERIES
Limited
n
th-order expansion
SERIES has three arguments: an expression dependent on
a variable, an equality (the variable
x = the value a to
which you want to calculate the expansion) and a whole
number (the order
n of the limited expansion).
You can omit the name of the variable and the = sign
when this name is in
VX ).
SERIES returns the limited n th-order expansion of the
expression in the vicinity of x = a .
•
Example — Expansion in the vicinity of x=a
Give a limited 4th-order expansion of cos(2 · x )
2
in the
vicinity of .
For this you use the SERIES command.
x
π
6
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=
hp40g+.book Page 24 Friday, December 9, 2005 1:03 AM