ɪf ðə stˈeɪt ᵻkwˈeɪʒən ɪz kwɑːdɹˈæɾɪk ðˈɛn ðə pɹˈɑːbləm ɪz nˈoʊn æz ðə kwɑːdɹˈæɾɪkkwɑːdɹˈæɾɪk ɹˈɛɡjʊlˌeɪɾɚ kjˌuːkjˌuːˈɑːɹ.
If the state equation is quadratic then the problem is known as the quadratic-quadratic regulator (QQR).