x[tex] x^{2/3} + y^{2/3} = a^{2/3} [/tex]
using [tex] \frac{d}{dx}( x^{n} ) = n x^{n-1} [/tex]
[tex] \frac{2}{3} x^{-1/3} + \frac{2}{3} y^{-1/3} \frac{dy}{dx} = 0[/tex] ....since rhs is a constant
note that jere i'm assuming that differentiation is done wrt x and a is a constant
