whats the difference between explicit functions and linear functions?

Question

anonymous · Answer

An explicit function is a function of the form y = f(x).
A linear function is a function of the form y = ax + b.

anonymous · Answer

then why isn't a linear function explicit?

anonymous · Answer

y=2x+1 is an explicit function,but it also looks like a linear function,how do i differ?

anonymous · Answer

i have no real idea what this question is asking, but 
$$y=2x+1$$ is not a function, it is an equation

anonymous · Answer

A linear function written as y = ax + b is an explicit function.

anonymous · Answer

ok,thankyou emarald000.i got it!

anonymous · Answer

you can certainly make it into a function by saying 
$$f:=\{(x,y)|y=2x+1\}$$ for example or even 
Let 
$$f(x)=2x+1$$

anonymous · Answer

@satellite: That is what i meant,you gave it a better representation though.