You are Here: Home >< Maths

# general graph transformation watch

1. need help in this question ( will upload question after a sec)
as i am confused about part c
y=-f(x)+4

as there any rule which transformation should i do before and which do after
if i do the transformation of +4 ( move up 4 units) and then do -(fx)
it will give points
-2,-4
-1,-8
0,-7 i try to show in the graph ( top corner)

and if i do -f(x) first and then +4 it will give points
-1,0
0,1

why ? what i am doing wrong?/
2. RDKGames
Desmos
3. I would say do -f(x) first and then +4, but you should wait for a reply from RDKGames, Notnek or Zacken.
4. (Original post by Desmos)
I would say do -f(x) first and then +4, but you should wait for a reply from RDKGames, Notnek or Zacken.
You're correct

@OP, if you do +4 first you go from f(x) to g(x) = f(x) + 4 then (-1) gives h(x) = -4 - f(x) which is a different thing
5. (Original post by Zacken)
You're correct

@OP, if you do +4 first you go from f(x) to g(x) = f(x) + 4 then (-1) gives h(x) = -4 - f(x) which is a different thing
OP, this may confuse you, so I would recommend you don't read this.

But does
6. (Original post by Desmos)
OP, this may confuse you, so I would recommend you don't read this.

But does
Yes
7. (Original post by Zacken)
You're correct

@OP, if you do +4 first you go from f(x) to g(x) = f(x) + 4 then (-1) gives h(x) = -4 - f(x) which is a different thing
1. Translation in x f(x+a)
2. Stretch in x f(ax)
3. Reflect in x -af(x)
4. Reflect in y f(-ax)
5. Stretch in y af(x)
6. Translate in y f(x)+a

Desmos

is that order id fine???
8. (Original post by Zacken)
You're correct

@OP, if you do +4 first you go from f(x) to g(x) = f(x) + 4 then (-1) gives h(x) = -4 - f(x) which is a different thing
Qer if Zacken's explanation confuses you, here's another way to look at it:

let f(x) = y
then -f(x) + 4 = -y + 4

But if we did +4 first, this is what happens:

y → y+4 → -(y + 4) = -y - 4 = -f(x) - 4: Not what we were looking for
9. (Original post by Qer)
1. Translation in x f(x+a)
2. Stretch in x f(ax)
3. Reflect in x -af(x)
4. Reflect in y f(-ax)
5. Stretch in y af(x)
6. Translate in y f(x)+a

Desmos

is that order id fine???
The order of operations should suffice.
10. I x -a I means both x and a are positive

so x+a =0
then x=-a???
11. (Original post by Qer)
I x -a I means both x and a are positive
No it doesn't

so x+a =0
No?
if and only if . So if and only if
12. (Original post by Qer)
I x -a I means both x and a are positive

so x+a =0
then x=-a???
|x-a| means that whatever is between the || now becomes non-negative.
13. (Original post by Desmos)
|x-a| means that whatever is between the || now becomes non-negative.
This is what I am saying
Isn't it?
14. (Original post by Qer)
This is what I am saying
Isn't it?
No. You are saying that and which is not what means
15. did i need to know how to find value of a reciprocal function without using a calculator for c3?? because Edexcel book have questions to find values without using calculator

like sec240??
16. (Original post by Qer)
This is what I am saying
Isn't it?
It becomes non-negative because the sign of whatever's inside changes if it's negative. So
17. (Original post by Qer)
did i need to know how to find value of a reciprocal function without using a calculator for c3?? because Edexcel book have questions to find values without using calculator

like sec240??
No. How would they know whether you have used a calc or not if you are allowed to use a calc on the paper...?
18. (Original post by RDKGames)
No. How would they know whether you have used a calc or not if you are allowed to use a calc on the paper...?
Yeah....I spend more than 1 and half hour on these....lol😫😫

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: July 22, 2017
Today on TSR

### Are you living on a tight budget at uni?

From budgets to cutbacks...

### University open days

1. University of Cambridge
Wed, 26 Sep '18
2. Norwich University of the Arts
Fri, 28 Sep '18
3. Edge Hill University
Faculty of Health and Social Care Undergraduate
Sat, 29 Sep '18
Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams