GCSE maths non calc- Direct/Inverse proportions?!

tashie1987

Just seen these on a list which someone wrote on here, of topics which are likely to come up. Can't find them in my edexcel revision guide, could someone please explain or gives me a website which explains?
Thank you!

Reply 1

ydhdfhfghaghgahgfh

x is directly proportional to y:
x = ky

x is inversely proportional to y:
x = k/y

That's all you really need to know...

k is a constant. When they ask you to write the formula for proportion, you always have to work out k.

For example, for the first one, if they say when x is 100, y = 50.

100 = 50k
k = 100/50 = 2

x = 2y

Reply 2

Bjoorn

11

also read the question carefully, if it says y squared or the square root of y then it is x=ky^2 or x=k(squareroot of y)

Reply 3

ydhdfhfghaghgahgfh

Also, the "square of x", means x^2, not root(x).

Reply 4

laurenlodge

19

This might help - it's a scan of my revision guide page - it's Edexcel (linear) as well.

The left side is slightly hard to read but it is possible. (If you can't read something, pm me and I'll have a look!)

(And you need to zoom to read the text!).

maths6.jpg213.2KB

Reply 5

tashie1987

OP

Thank you guys that's great!

Reply 6

moneyballs2

14

lozz2601

This might help - it's a scan of my revision guide page - it's Edexcel (linear) as well.

The left side is slightly hard to read but it is possible. (If you can't read something, pm me and I'll have a look!)

(And you need to zoom to read the text!).

Hi,

That's a very good book you have there, what is the name (or ISBN)?

I have BBC Bitesize & CGP and they are both crap IMO.

Cheers :smile:

Reply 7

ah1709

Original post by lozz2601

This might help - it's a scan of my revision guide page - it's Edexcel (linear) as well.

The left side is slightly hard to read but it is possible. (If you can't read something, pm me and I'll have a look!)

(And you need to zoom to read the text!).

I have been stuck with this for such a long time, this really helped. Thank you :smile:

Reply 8

pantsontheground

Original post by tashie1987

Just seen these on a list which someone wrote on here, of topics which are likely to come up. Can't find them in my edexcel revision guide, could someone please explain or gives me a website which explains?
Thank you!

Where is the list of things likely to come up? Could you give me the link please? thank you :smile:

GCSE maths non calc- Direct/Inverse proportions?!

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