chanandler
Badges: 1
#1
Report Thread starter 15 years ago
#1
I need to know what f(x) means and why we use it in maths? I'm really stuck.
Thanks in advance
0
reply
Mustard-man
Badges: 18
Rep:
?
#2
Report 15 years ago
#2
'function of x'
f(x) basically means y, and f'(x) means dy/dx
The x can have a value, so for example, f(x) = 2x + 1, then f(1) = 3

that is as good as I can explain it!!!
3
reply
Mustard-man
Badges: 18
Rep:
?
#3
Report 15 years ago
#3
O, and f(x) is the 'range' (range and domains come in at A2 (ocr spec.))
0
reply
Sasuke!
Badges: 14
Rep:
?
#4
Report 15 years ago
#4
f(x) is just something that is done to "x", its a function
1
reply
*River
Badges: 15
Rep:
?
#5
Report 15 years ago
#5
(x) is the basic equation of the graph, say, x² + 4x +4.

The F is what you are doing to it, eg translating it up 2, or stretching it etc. There are equations for this but I've forgotten them!
0
reply
Niaya
Badges: 13
Rep:
?
#6
Report 15 years ago
#6
(Original post by gordon2002)
'function of x'
f(x) basically means y, and f'(x) means dy/dx
The x can have a value, so for example, f(x) = 2x + 1, then f(1) = 3

that is as good as I can explain it!!!
Tbh thats about as good as most people would be able to do and i didnt know that f'(x) was dy/dx
0
reply
Chewwy
Badges: 17
Rep:
?
#7
Report 15 years ago
#7
remember the little function boxes you did when you were like 10. x goes in, f(x) comes out. the function could be, say, adding 5, dividing by two... whatever.
1
reply
AlphaNumeric
Badges: 10
Rep:
?
#8
Report 15 years ago
#8
(Original post by heninacoop)
(x) is the basic equation of the graph, say, x² + 4x +4.

The F is what you are doing to it, eg translating it up 2, or stretching it etc. There are equations for this but I've forgotten them!
Completely wrong. As Chewwy says, x goes in, f(x) comes out. You can use g(x), h(x), Ø(x), Ω(x), Bob(x), Ostrich(x), anything you like. The letter, symbol or even word before the (x) is simply a way of allowing you to know which function it is you are talking about. You can define f(x) to be anything you like, the "f" label is irrelevant of what the function is.

The letter within the brackets is the variable. You can have multiple variables too, like f(x,y), H(x,y,t) or anything you like really (but not repeated letters!).
1
reply
PIPSarah
Badges: 0
#9
Report 15 years ago
#9
f(x) is the gradient function isnt it? you use it to find gradients using differentiation?
0
reply
Ads.
Badges: 7
Rep:
?
#10
Report 15 years ago
#10
(Original post by PIPSarah)
f(x) is the gradient function isnt it? you use it to find gradients using differentiation?
No you are wrong. READ the posts above before replying.f'(x) would be the gradient
0
reply
button16
Badges: 1
Rep:
?
#11
Report 15 years ago
#11
remember the little function boxes you did when you were like 10. x goes in, f(x) comes out. the function could be, say, adding 5, dividing by two... whatever.
That's great you deserve some rep I've been having trouble understanding this.
0
reply
hawaiian_angel
Badges: 0
#12
Report 15 years ago
#12
(Original post by chanandler)
I need to know what f(x) means and why we use it in maths? I'm really stuck.
Thanks in advance

f(x) just means a 'function' of 'x',
0
reply
shaneal
Badges: 1
Rep:
?
#13
Report 3 years ago
#13
i need help
0
reply
조남호
Badges: 0
Rep:
?
#14
Report 3 years ago
#14
I'm Korean high school student.and i have more questions after reading all the replys...f(x) means function basically as we all learned...but when we think about the polynomial,the question says 'the polynomial f(x)=3x 4....'I want to ask that f(x)'s meaning...
0
reply
Galibmehedijami
Badges: 7
Rep:
?
#15
Report 2 years ago
#15
If f(x+4)=4x then find f(x)?
Can anyone explain how its done?
0
reply
LowIQ
Badges: 8
Rep:
?
#16
Report 2 years ago
#16
(Original post by Galibmehedijami)
If f(x+4)=4x then find f(x)?
Can anyone explain how its done?
I may be wrong but what you want to do is to do the reverse of the change in the input x. Eg. in this function it shows that 4 is added to the input as shown with f(x+4) but to get f(x), you do the opposite so subtract 4 to get back to the original input, x. Therefore you get f((x+4) - 4) which is f(x) as +4-4 is 0. Thus with the 4x, the x here would be substituted for (x-4) which results with 4(x-4) and if you expand that, you get 4x-16. So f(x)=4x-16.
0
reply
Lighting girl
Badges: 1
Rep:
?
#17
Report 1 year ago
#17
Ya me to can someone help us
0
reply
Lighting girl
Badges: 1
Rep:
?
#18
Report 1 year ago
#18
But how I am still confused how does it become a 3
0
reply
Lighting girl
Badges: 1
Rep:
?
#19
Report 1 year ago
#19
What do u mean by f means functions
0
reply
Harry14
Badges: 11
Rep:
?
#20
Report 1 year ago
#20
It is a functions question where you have to substitute
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Following the government's announcement, do you think you will be awarded a fair grade this year?

Yes (308)
52.56%
No (278)
47.44%

Watched Threads

View All