mal_123
Badges: 9
Rep:
?
#1
Report Thread starter 2 days ago
#1
Name:  442D2996-EA80-4497-A0A5-14F527905C15.jpg.jpeg
Views: 10
Size:  21.2 KB

I don’t understand why the answer is -1
0
reply
Pangol
Badges: 15
Rep:
?
#2
Report 2 days ago
#2
(Original post by mal_123)
Name:  442D2996-EA80-4497-A0A5-14F527905C15.jpg.jpeg
Views: 10
Size:  21.2 KB

I don’t understand why the answer is -1
ff(6) means f(f(6)). So start by working our f(6), and then plug that answer into f again and see what you get.
1
reply
mal_123
Badges: 9
Rep:
?
#3
Report Thread starter 2 days ago
#3
For f(6) I got 15, but I don’t think it’s correct
0
reply
Pangol
Badges: 15
Rep:
?
#4
Report 2 days ago
#4
(Original post by mal_123)
For f(6) I got 15, but I don’t think it’s correct
It's not quite - can you explain how you get that?
0
reply
mal_123
Badges: 9
Rep:
?
#5
Report Thread starter 2 days ago
#5
21-2+2-6
0
reply
Pangol
Badges: 15
Rep:
?
#6
Report 2 days ago
#6
(Original post by mal_123)
21-2+2-6
You need to do 21-2|2-6|.
0
reply
mal_123
Badges: 9
Rep:
?
#7
Report Thread starter 2 days ago
#7
So do I multiply or add |2-6|?
0
reply
Pangol
Badges: 15
Rep:
?
#8
Report 2 days ago
#8
(Original post by mal_123)
So do I multiply or add |2-6|?
That last bit of the equation says 2|2 - x|, so you need to multiply by two. Then subtract what you get from the 21. This is normal BODMAS stuff, treat the modulus part as if it is a bracket, it has the same priority.
0
reply
mal_123
Badges: 9
Rep:
?
#9
Report Thread starter 2 days ago
#9
Oh thank you so much! I got 13 which I think is correct
0
reply
Pangol
Badges: 15
Rep:
?
#10
Report 2 days ago
#10
(Original post by mal_123)
Oh thank you so much! I got 13 which I think is correct
Now do f(13) and see what happens.
0
reply
mal_123
Badges: 9
Rep:
?
#11
Report Thread starter 2 days ago
#11
C
(Original post by Pangol)
That last bit of the equation says 2|2 - x|, so you need to multiply by two. Then subtract what you get from the 21. This is normal BODMAS stuff, treat the modulus part as if it is a bracket, it has the same priority.
Do you mind helping me with part c as well?
0
reply
Pangol
Badges: 15
Rep:
?
#12
Report 2 days ago
#12
(Original post by mal_123)
C

Do you mind helping me with part c as well?
They've drawn the graph of y = f(x) for you. If you are considering f(x) = k, you are considering the intersection points between the graph they have drawn and the graph y = k. What does this latter graph look like? Can you see when there would be exactly two intersection points?
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

How are you feeling now you've started university?

I'm loving it! (51)
13.93%
I'm enjoying it but I'm still settling in (94)
25.68%
I'm a bit unsure (63)
17.21%
I'm finding things difficult (127)
34.7%
Something else (let us know in the thread!) (31)
8.47%

Watched Threads

View All