Originally posted by prog_tom
what is f(x)? I noticed it's a function, but can anyone explain it to me? What am I suppose to do with f(x)=79x+y+7z; or something like that? How to graph that onto a real number line?
f(x) is a user defined function, with parameter x. You could equally have g(x), k(x), p(z), mFunc(s, t)... You define the function, and the parameters.

The actual function you specified would have three parameters, as it contains x, y and z variables. So:

f(x, y, z)=79x+y+7z

You can then say f(1,2,4) = 109, as 79*1 + 2 + 7 * 4 = 109.