What does fx mean in maths

Henrik supports the community 6, 13 13 gold badges 22 22 silver badges 30 30 bronze badges. MathEnthusiast MathEnthusiast 2 2 gold badges 9 9 silver badges 29 29 bronze badges. Whole numbers are not nonnegative numbers, either; they are natural numbers including 0. They have different definitions. Show 13 more comments. This is backed up by Wikipedia article on functions Sign up or log in Sign up using Google. Sign up using Facebook.

Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. Upcoming Events. Featured on Meta. Now live: A fully responsive profile. The unofficial elections nomination post. Linked Capital letters often represent antiderivatives. If you claim f is a function and then refer to another function F, you can't assume it will be understood that F is the antiderivative of f without stating so. But as for notation, you can use any notation you want, just as you can any variable you want.

There are conventions based on context but they are not set in stone. And it could meant anything the writer makes up as well. And that's all fine and makes sense. Add a comment. Active Oldest Votes. Simon Marynissen Simon Marynissen 1, 1 1 gold badge 8 8 silver badges 26 26 bronze badges.

Stella Biderman Stella Biderman Upcoming Events. Featured on Meta. Now live: A fully responsive profile. The unofficial elections nomination post. For instance, your graphing calculator will list different functions as y1, y2, etc, so you can tell the equations apart when, say, you're looking at their values in "TABLE".

In the same way, in textbooks and when writing things out, we use different function names like f x , g x , h x , s t , etc, to keep track of, and work with, more than one formula in any single context.

With function notation, we can now use more than one function at a time without confusing ourselves or mixing up the formulas, leaving ourselves wondering "Okay, which ' y ' is this one? Both functions have the same plug-in variable the " r " , but " A " reminds you that the first function is the formula for "area" and " C " reminds you that the second function is the formula for "circumference".

Remember: The notation " f x " is exactly the same thing as " y ". You can even label the y -axis on your graphs with " f x ", if you feel like it. Let me clarify another point. While parentheses have, up until now, always indicated multiplication, that is not the case with function notation. Contrary to all previous experience, the parentheses for function notation do not indicate multiplication. The expression " f x " means "a formula, named f , has x as its input variable". It does not mean "multiply f and x "!

Don't embarrass yourself by pronouncing or thinking of " f x " as being " f times x ", and never try to "multiply" the function name with its parenthesised input. In function notation, the " x " in " f x " is called "the argument of the function", or just "the argument".

So if they give you the expression " f 2 " and ask for the "argument", the answer is just " 2 ". Aside: Why is the input called the "argument"? The term "argument" has a long history. Originally, it was a logical term, referring to a statement that forwarded a proof or, in a less formal sense, a claim that was being used to try to convince somebody of something. Eventually, the term came to refer, in early scientific contexts, to any mathematical value that was needed as an input to other computations, or any value upon which later results depended.

In the twentieth century, when computer coding started becoming a thing, coders adopted the mathematical meaning to refer to inputs to their coding. In our mathematical context, the "argument" is the independent variable the one for which you pick a value, usually being the x -value and the function's output is the dependent variable the one whose value depends upon whatever was plugged in, usually being the y -value.

I'll do the second part first. The argument is whatever is inside the parentheses, so the argument here is s. The function name is the variable that comes before the parentheses. In this case, then, the function name is h. The argument is whatever is plugged in.

In this particular unusual case, the variable being plugged in is " y ". After all, there's no rule saying that y can't be the independent variable.

The function name is what comes before the parentheses, so the function name here is g.