Fnroot; Frac - HP 39g Master Manual

FNROOT(express.,guess)
This function is like a mini version of the Solve
aplet. If you feed it an algebraic expression
and an initial guess it will start from your guess
and find the value which makes the expression
zero. Don't bother. It's a lot easier to use the
Solve aplet. This is a tool for programmers so that they can access the Solve
abilities within programs.
You need to tell it what variable to expect in
the expression, in addition to providing it with
an initial guess. If there is only one answer
then any guess will do, but if more than one
solution is possible then more care needs to
be taken with your guess to ensure that it is in
the neighborhood of your desired solution.
Eg. (a) Solve
x
Use: FNROOT(X
d
(b) Solve
3
Use: FNROOT(D/3-5-3D/4-1,D,0)
As with Solve, if your expression involves more than one variable then
whatever values are currently in memory are used for the other variables.
See also: QUAD,
FRAC(num)
This function gives the decimal part of any number, discarding the integer
part.
Eg.

FRAC(3.45) = 0.45

FRAC(1234.03456) = 0.03456
See also:
INT,FLOOR,CEILING,ROUND,TRUNCATE,FRAC
− − =
2
3 x 5 0
2
-3X-5,X,2)
3 d
− = +
5 1
4
POLYROOT
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