Solve equations witch contains absolute values

[Bossebo]

Hi

(I apologise for my bad english!)

I have a question about mathcad. I have a equation loking something like this:

f(x)=N/A+M*(x-y)/W

witch I like to solve for f(x)=0
with other words, I like to find the x for witch f=0

The problem is that the term (x-y) should be the absolute value and to me it looks like mathcad cant solv the equation using f solve,x-> when it contains absolute values

I then tried to rewrite the term like this:

squarrot( (x-y)^2)

witch of corse is the same but I thought this way to write it maight help but NOP it dident. Matchad was unable to solve the equation so my question is:

How do i get Mathcad to solve equations witch contains absolute values?

 

[IRstuff]

You can't, in general. Such functions are highly discontinuous, and the only solution is to partition the problem and solve each partition separately.

TTFN

FAQ731-376

 

[GregLocock]

Hopefully one or three of M W N and A are negative.

Then it is easy, even if Mathcad can't do it.


mod(x-y)=-N/A*W/M

x=y+(N*W/M/A)^2











Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[Bossebo]

Hi again

Thanks for quick answers!

Unfortunately I cant tell whether zero, one or two of M, W, A and N will be negative. I guess I have to find another way too get around the problem.

Thanks anyway!

 

[Occupant]

I must be missing something, but what?

 

[PNachtwey]

Occupant has the solution but some times I find that using the assume directive helps too.

Peter Nachtwey
Delta Computer Systems

http://www.deltamotion.com