Helping solving this problem symbolically in Prime 3.0

[ptc-5867542]

I need to solve this in terms of r. I clearly am missing something basic. Any help would be greatly appreciated.

[Werner_E · Accepted solution]

Solve what?

BTW, if you define a1(r):=... and then e(r):=... you have to write a1(r) etc. on the RHS of the assignment, too. This applies to all of your function definitions.

[ptc-5867542]

Thank you for the help. That was the piece I was missing.

To answer your question, I was trying to solve for the delta-V for the hohmann transfer in terms of r.

I ended up solving in terms of r, Re, and mu.

I attached the updated document, if anyone is interested.

[Werner_E]

Fine, so I answered the question without being aware of.

I wouldn't call it solving what you do in the sheet, though. If you have x+1=3 and you are searching x, thats what I would call solving. Therefore the quertion of mine.

BTW, the definition of a2 is still missing the arguments on the RHS, but its never used anyway.

[ptc-5867542]

I couldn't agree more.

The "general solution" as the problem refered to it is of absolutely no use to anyone.

However, it did encourage me to sit down and play with Mathcad a bit.

Thank you again for the help.

[Werner_E]

While your sheet is working it may look a bit cluttered as of all those function arguments.

If you are not in need for the intermediate results you may consider putting all calculations into one function for better readability:

[ptc-5867542]

I am a bit old school, so the way I generally go about laying it out is exactly like I would write it out in a notebook. However, I can see the value in condensing it for certain situations. How does one go about making a single function like that?

[Werner_E]

How does one go about making a single function like that?

Not sure If I understand the question. The function includes step by step the assignments you made. As its all in one function we don't have to male them them functions but just simple variables, which are dependable on the arguments of the function. So its written as it ayou may find it in textbooks or you write it yourselft - we all are sloppy now and then and forget to write out all the function arguments and dependencies. We often are not aware that we are basically dealing with a function when we write u=2*r*pi at the top and later use this "formula" to calculate the circumfence of a circle with radius 10 cm.

Or was the question meant as of how to type and create a function? In Prime its rather cumbersome (as opposed to "real" Mathcad as you have to go to ribbon menus all the the time. You have to use th programming menu in the first ribbon to acces all those pragramming keywords (of course there are keybpard shortcuts and if you are using an English keyboard, they may even work as stated.

Turning calculations into functions can be a most powerful tool and very handy and convenient.