Consider the following equation.
x=at2, y=2atatt=1
Differentiate both side w.r.t x and y we get.
dxdt=2at.....(1)
dydt=2a..........(2)
Divide eq.(1)in eq. (2) we get.
dydx=2at2a......(3)
dydx=t
Put the value of ′t′ in eq. (3) we get.
dydx=1
dy=dx
Hence, this is the correct answer