Awais_
Badges: 2
Rep:
?
#1
Report Thread starter 4 years ago
#1
If f is inversely proportional to g² and f = 8 when g = -2, what is f when g = 4?


I don't understand inverse proportinality, someone please teach me!!

Thanks.
0
reply
qwertzuiop
Badges: 2
Rep:
?
#2
Report 4 years ago
#2
(Original post by Awais_)
If f is inversely proportional to g² and f = 8 when g = -2, what is f when g = 4?


I don't understand inverse proportinality, someone please teach me!!

Thanks.
2.

Isn't new years eve mathematics spectacularly fun?
0
reply
Awais_
Badges: 2
Rep:
?
#3
Report Thread starter 4 years ago
#3
(Original post by qwertzuiop)
2.

Isn't new years eve mathematics spectacularly fun?
Haha yup, if I want to change my C grade to an A* grade I need to do Math all year round.
0
reply
EricPiphany
Badges: 15
#4
Report 4 years ago
#4
|g| is twice as big so g^2 is four times as big... So f is 4 times smaller (divide by 4, inversely proportional).
0
reply
Shad0wfax
Badges: 2
Rep:
?
#5
Report 4 years ago
#5
Hey! Let me give you a simple example.
When a is proportional to b,
a=kb, where k is a constant(you can put any random letter)
Then plug in the values you have for a and b and find k. Then use that k value for what you need to calculate.

When a is inversely proportional to b,
then a is proportional to 1/b(as you are getting the inverse of b)
which implies that a=k/b, where k is a constant
Then plug in the values of a and b and find k. Then use the k value for further calculations.

Back to your question...if f is inversely proportional to g^2,
then f is proportional to the inverse of g^2 (i.e. 1/g^2)
which implies f=k/g^2
since f=8 and g=-2,
f=k/g^2
8=k/(-2)^2
8=k/4
k=32

Now you have k. Thus, f=k/g^2
f=32/4^2 (since g=4)
=32/16
=2

I hope that helps! Good luck!
2
reply
Awais_
Badges: 2
Rep:
?
#6
Report Thread starter 4 years ago
#6
(Original post by Shad0wfax)
Hey! Let me give you a simple example.
When a is proportional to b,
a=kb, where k is a constant(you can put any random letter)
Then plug in the values you have for a and b and find k. Then use that k value for what you need to calculate.

When a is inversely proportional to b,
then a is proportional to 1/b(as you are getting the inverse of b)
which implies that a=k/b, where k is a constant
Then plug in the values of a and b and find k. Then use the k value for further calculations.

Back to your question...if f is inversely proportional to g^2,
then f is proportional to the inverse of g^2 (i.e. 1/g^2)
which implies f=k/g^2
since f=8 and g=-2,
f=k/g^2
8=k/(-2)^2
8=k/4
k=32

Now you have k. Thus, f=k/g^2
f=32/4^2 (since g=4)
=32/16
=2

I hope that helps! Good luck!
Thanks a lot mate!!
👍
0
reply
Shad0wfax
Badges: 2
Rep:
?
#7
Report 4 years ago
#7
(Original post by Awais_)
Thanks a lot mate!!
👍
You're welcome! and have a HAPPY NEW YEAR!!! It's 12.08 am here that's why I'm wishing you right now
0
reply
Awais_
Badges: 2
Rep:
?
#8
Report Thread starter 4 years ago
#8
(Original post by Shad0wfax)
You're welcome! and have a HAPPY NEW YEAR!!! It's 12.08 am here that's why I'm wishing you right now
HAPPY NEW YEAR to you too my friend, in England it's 21:11. What country are you in atm?
0
reply
Shad0wfax
Badges: 2
Rep:
?
#9
Report 4 years ago
#9
(Original post by Awais_)
HAPPY NEW YEAR to you too my friend, in England it's 21:11. What country are you in atm?
Thanks! I'm in Kenya right now
0
reply
Awais_
Badges: 2
Rep:
?
#10
Report Thread starter 4 years ago
#10
(Original post by Shad0wfax)
Thanks! I'm in Kenya right now
Alright, cool!

Best wishes for 2016!
0
reply
Shad0wfax
Badges: 2
Rep:
?
#11
Report 4 years ago
#11
(Original post by Awais_)
Alright, cool!

Best wishes for 2016!
Thank you!
May you have a wonderful new year!
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

University open days

  • University of Groningen
    Undergraduate Open Day Undergraduate
    Fri, 31 Jan '20
  • Sheffield Hallam University
    Course Open Day Undergraduate
    Sun, 2 Feb '20
  • University of Bath
    Postgraduate Virtual Open Day 5 February 2020, 11:00-15:00 (UK time) Postgraduate
    Wed, 5 Feb '20

Why do you want to do a masters?

Great for my career (77)
37.2%
I really love the subject (53)
25.6%
I don't know what else to do (26)
12.56%
I can't get a job (15)
7.25%
My parents want me to (5)
2.42%
I don't know... I just do (31)
14.98%

Watched Threads

View All