Thread: Inversely proportional!?!

Q is inversely proportional to the cube of T

When T=5, Q=12.6



It's as if someone added a decimal point and then added a 0.1 although it is never so with maths....thankfully.

Hello, Mukilab!

Do you really understand proportionality?

is inversely proportional to the cube of .

.[1]

When

Substitute into [1]: .

Therefore: .

Originally Posted by Soroban

Hello, Mukilab!

Do you really understand proportionality?

.[1]


Substitute into [1]: .

Therefore: .

No I did not understand proportionality but now I do understand, thank you.
If I only have T, let's say it is 3. How would I calculate Q. Surely I need this k (where did you get it from?)

Proportionality afaik requires a variable equal to another variable multiplied (or divided) by a constant.

; is proportional to . An inverse proportionality would be

So the constant either has to be given, or you need to be able to calculate it from the information you have.

Originally Posted by dkaksl

Proportionality afaik requires a variable equal to another variable multiplied (or divided) by a constant.

; is proportional to . An inverse proportionality would be

So the constant either has to be given, or you need to be able to calculate it from the information you have.

The information given is: T is now 3. Work out Q. GCSE paper :/ don't think they made a mistake

They did mention it was inversely proportional, right? That means;

Originally Posted by Soroban

even though isn't written anywhere you know there is a constant to define the relationship between Q and T. You can also call that constant whatever you like. It's basically rule 1 of algebra.