On what interval (s) is the curve dt 0 12 3t + 8 concave downward? Answer (in interval notation): help (intervals) Preview My Answers Submit AnswersUse the Fundamental Theorem of Calculus to find the derivative of -sin () h(z) = (cos(t# ) + t) dt h'(z) - Enter a function as your answer. Make sure that your syntax is correct, i.e. remember to put G U cessary * (, ), etc.] For more help see: WeBWork functions