# Testing for Unit Roots with Quadratic Trends in Stata

I understand that Dickey-Fuller test could test for a unit root with drift and deterministic time trend. $$\nabla y_t = a_0+a_1t+\delta y_{t-1}+u_t \$$

What are the tests for unit root with quadratic trends? In particular, how can I test it in Stata? $$\nabla y_t = a_0+a_1t+a_2t^2+\delta y_{t-1}+u_t \$$