How to plot y=-5x?

[Brian Feeny]

I am trying to get started in graphing on my HP49g+, I have Dr.
Urroz's books on order and hopefully that will help me alot. Can
someone tell me the steps necessary to plot y=-5x? How about y=-5x
(x<=0)?

Brian

[Virgil]

In article <7bb5a5d1.04091...@posting.google.com>,
bfe...@mac.com (Brian Feeny) wrote:

For starters, consider the equation 'Y=-5*X'

Using lower case 'x' without changing the independent graphing variable
will leave you with a blank graph.

'-5x' without a multiplication sign will also cause problems.

[Speed]

> > I am trying to get started in graphing on my HP49g+, I have Dr.
> > Urroz's books on order and hopefully that will help me alot. Can
> > someone tell me the steps necessary to plot y=-5x? How about y=-5x
> > (x<=0)?

The manual shows the basics of graphing. For the inequality, I'd just
tell it to graph Y(X)=-5*X*(X<=0). Since the HP thinks of true and
false as 1 and zero respectively, the equation evaluates to zero as
long as X is less than zero.

It's not very rigorous, or really even right, but it helps visualize
piecewise functions. Because it's technically wrong, it doesn't help
with things like Laplace transforms involving Unit step functions.

[Glen]

You suggested multiplying by a bool evaluation when graphing in a
restricted domain. On my TI83, i often instead devided by the same
bool value. It will yield a similar result, however there will be no
value for the function in this case where x>0, possibly giving a more
desireable result. But additionally, an extention on this method for
graphing piecewise functions in a single equation deffinition may be
very useful. Thanks for your thoughts, and i hope that this helps

[Veky (hp49G)]

Of course, hp49G can plot also the full UsrRPL programs... with
IF...THEN...ELSE , and even WHILE branching (if you want to make it
:real: slow;).

[Veli-Pekka Nousiainen]

"Veky (hp49G)" <ved...@gmail.com> wrote in message
news:cibgmf$t...@odbk17.prod.google.com...

> Of course, hp49G can plot also the full UsrRPL programs... with
> IF...THEN...ELSE , and even WHILE branching (if you want to make it
> :real: slow;).

and
if you need to program a function, IFTE is there:
<< -> x'IFTE(x>5,SQ(x),COS(x))' >>
[VPN]