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# question about differentiation (rates of change) watch

1. Hi guys,

I have a query about a 'rates of change' question.

Basically, the question was to find
From the question, i have obtained the changing rate of volume as and .

At first, to find out , i used the chain rule connection: . ( i flipped the over) But it gave me a wrong answer, i should have flipped instead.....

The question I want to ask is, is it wrong to flip the as it has 'dt' as denominator?
2. (Original post by strwbry_short_cake)
At first, to find out , i used the chain rule connection: . ( i flipped the over) But it gave me a wrong answer, i should have flipped instead.....

The question I want to ask is, is it wrong to flip the as it has 'dt' as denominator?
The method you used would give

It doesn't really matter which of the differentials you flip over, but using your method, to get you have to do
3. ah yes of course it would...=S
thanks so much!

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