Find dy in the following cases:
dx
(i) x = 2at,
y = at2​

Sorry if i'm wrong, I'm still half confused by what you mean in this question.

if you mean to find the derivative when x=2*at and y=(at)^2 then y=(x/2)^2 and the implicit derivative d/dx (y) is x/2. If you could post a screenshot or a picture of the actual problem I think it will help.

go on the tube you might find some information there

you didn't give me the choices, so i will just give you the graph so you can look at your choices and choose the right one.