I'm just a freshman and I'm not good at math. Ask some experts: What does 1.f(x) mean? What about g(x)? Is it the same? 2

F(x) is Y in middle school, but the object is more specific.

F is the law of correspondence and x is an independent variable.

F(x) represents the output of the independent variable x under the corresponding law f.

F(x+2) represents the output with independent variable (x+2) under the corresponding rule F.

Similarly, g(x) represents the output of the independent variable x under the corresponding law g, where g and f can be the same or different.

(x) and x, how do you say this? F () is a whole and cannot be decomposed.