Homework, um? If it's a programming homework, this is definitely not a job for a newbie. The problem is that you any formula you want tocalculate must be seen by compiler at compile-time. If you want to enter a formula in run-time, you must parse it yourself, i.e. read the formula as a character string, analyse the string (whether any substring is a variable, operator (+,-,*,bracket) or number), break it into elementary operations and calculate each intermediate result yourself.
You can find the program which does exactly that here:
http://smidgley.customer.netspace.net.au/fortran/
but I somehow doubt that this was really your assignment :smileywink:.
Jugoslav
