We have given, x=3cosθ -2cos³θ , y=3sinθ-2sin³θ

Now, differentiate both the equation w.r.t. x then we get

x=3cosθ -2cos³θ

---(i)

And, for y=3sinθ-2sin³θ

---(ii)

Therefore,

Hence, dy/dx=cot θ