rate of chance

hi, can somebody check this please

the volume of a sphere is increasing at the rate of 200 cm
find in terms of pi the rate of increase of the radius when the radius is 5

dv/dt = 200

dr/dt = dv/dt x dr/dv

formula for volume of a sphere 4/3 x pi x r^2
differential = 4 x pi x r^2

200 x 4 x pi x r^2
r=5
200 x 4 x pi x 25 = 20,000 pi

Do you think that these are the same thing?

not sure, i have no idea what these things mean tbh

Are you doing A Level Maths?

yes

In Y13?

If so

Surely you know what $\dfrac{dV}{dr}$ and $\dfrac{dr}{dV}$ mean

And, surely you know that the next line of working to $V = \frac{4}{3} \pi r^3$ should have started with one of them rather than "differential"

i am in y13, but I don't know what they mean

Then you need to speak to your teacher

This is a basic understanding of what the derivative means

ill ask then, had a look on my maths but couldnt find much about it

I have a feeling that $\dfrac{dy}{dx}$ was not well defined for you in Y12

However, it is shocking if the differential function has not been explained as a rate of change now that you are doing this work