Symbolic value propigation

[creed-2]

Can a variable's symbolically obtained value be propagated to future uses of that variable?

I want my second expression to see c2 as zero.

[Werner_E]

Maybe that way:

There are sure other ways but you have to be more precise as to what you are really after at at the end.

Looks you have to solve a system of equations?

Next time please attach your worksheet, but as you are using Prime, you still have to provide a picture or a pdf printout because many of us (like me) cannot reat P3.1 files with our P.3.0 version of Prime.

WE

[RichardJ]

Yes, but not like that. The symbolic evaluation gives f''(0) as c2. The boolean equals and the 0 have no effect at all, they are just cosmetic, so c2 has not been assigned any value. The only way to assign a value to a variable is with a numeric assignment. That can be coupled with a symbolic operation, for example a solve, but in your case I can't tell you exactly what to do without seeing more of the worksheet.

[creed-2]

I've attached a simplified example of my question. If I want to use "x" later in my worksheet I have to redefine it after it's symbolically solved.

If my "y" or "w" variables change, the new value for "x" is no longer propagated.

Is there a technique that would keep me from refining "x" every time is value is effected?

*I'd add an attachment of the original file but am not seeing an option to do that, what am I missing?

[RichardJ · Accepted solution]

Use a numeric assignment with the symbolic solve:

To attach a file click on "Use advanced editor" at the top right of the edit dialog (it's not very obvious!).

[MJG]

append "x:=" to your equation that solves for x:

P.S. to add an attachment, select "Use advanced editor"

[MJG]

Perhaps you could use this general solution to your original post:

Or, if w & L are previously defined, you could use this case-specific form instead: