ðə kˈeɪs wˌɛɹ ðə sˈɪstəm daɪnˈæmɪks ɑːɹ dᵻskɹˈaɪbd baɪ ɐ sˈɛt ʌv lˈɪnɪɹ dˌɪfɚɹˈɛnʃəl ᵻkwˈeɪʒənz ænd ðə kˈɔst ɪz dᵻskɹˈaɪbd baɪ ɐ kwɑːdɹˈæɾɪk fˈʌŋkʃən ɪz kˈɔːld ðɪ ˌɛlkjˈuː pɹˈɑːbləm.
The case where the system dynamics are described by a set of linear differential equations and the cost is described by a quadratic function is called the LQ problem.