Solving with multiple unknown variables & more

[leprechaun]

hello everybody!

Thank you for the Information given in this thread. I started to play with the functionality and I am very impressed. You need to know about the syntax but then solve() is really powerful. Sadly, like expected, I ran into Problems later... Maybe you can help me on how to do it correctly or give me some magic pragma again that does the job:

What I did: Define two functions.

Ekin(m,v):=0.5*m*v^2
Epot(m,h):=m*9.81*h

You can calculate energies at once for 70 kg and 15 m/s by evaluating the functions. Ekin(70,15)

I can save the weight into m. m:=70; And calculate Ekin(m,15).

I can use solve() to equal Ekin and Epot (It took me a while to realize that I have a function and must use the following Syntax)

solve( Ekin(m,v)=Epot(m,h),v ).
There are two solutions, of course. BUT I found the way to pass assumption to the calculator.

assume( v>=0 )
solve( Ekin(m,v)=Epot(m,h),v ). Only one solution! GREAT!



1) With the Function App there are problems. I cannot really find out what is going wrong. Maybe someone can help me!
The function plots functions of one independant variable. So far so good. Assignment of e.g. Ekin(m,v) to the app fails although it is a function of one independant. Remember I assigned m:=70, so that is a constant. Only independant var is v.
How do I copy Ekin(m,v) to the app to have it plotted? In practice functions of one independant variable are often seen - but only because other variables can be defined to constants....


2) Now if I define Ekin2(v):=0.5*70*v^2 because I did not find the correct way to copy the function into the app. Not practical at all, but what should I do.
Assignment to F1 now works as described:
F1:=Ekin2.
No variables like F1(X) needed. That is some auto-Transformation going on.
BUT the calculator Forgets about my assumption about v i.e. assume(v>=0)! Is that a bug?


Thanks for help in advance