How to store an equaion in a variable?

[arabajamelabañera]

Dear all,
I am new to the TI-Nspire CX CAS. Could you advice me on how to store an equation in a variable? Mathematica uses ":=" and "==", e.g.

Code: Tout sélectionner

myeq := 1/a == b * log(a + 4)

in order to use it later on in an expression like

Code: Tout sélectionner

solve(myeq,a) | b = 10

Thank you for advice.

[Hisham]

Best,
Hisham

[arabajamelabañera]

Hi Hisham,
I don't get it... where has "eq"been assigned, and what is "subst"?
Could you give me a more concrete example or explain how it is supposed to work?

[Bisam]

First, the affectation symbol is :=, would it be for a function or a variable.
Then, the test for equality is done with =, not == which will run to a syntax error.

E.g. :

Code: Tout sélectionner

myeq := 1/a = b * log(a + 4)
solve(myeq,a) | b = 10

[arabajamelabañera]

Hi Bisam, thank you for your reply.
Yes, I agree. But when I type it the way you propose, I get an error:
"Argument must be an expression."
Which implies that equations can not be stored and recalled in a convenient way?!?

[nspiredev500]

Maybe you mistyped something, it works for me.

[arabajamelabañera]

Thank you all for your time.
Miraculously, it is working now...
a := b + c = d
gives
b + c = d
I really do not know, why I had to write this post.