3. -3 points SCalcET8 10.2.011 My Notes Ask Your Teache Find dy/dx and d2yjdx2 x-2+9, y-2+3t dy dx dx2 For which values of t is the curve concave upward? (Enter your answer using interval notation.) Need Help? Read It Talk to a Tutor 4. -12 points SCalcET8 10.2.017 y Notes Ask Your Teache Find the points on the curve where the tangent is horizontal or vertical. If you have a graphing device, graph the curve to check your work. (Enter your answers as a comma-separated list of ordered pairs.) x-3-3t, y-2-4 horizontal tangent (x, y) = vertical tangent (x, y) Need Help?Read It Talk to a Tutor