(3 points) Consider the parametric curve given by x = t+ In(t), y = 10t - 10 In(t) (a) Find dy / da and day / dac2 in terms of t. dy/ dx = day/ dac2 = (b) Using "less than" and "greater than" notation, list the t-interval where the curve is concave upward. Use upper-case "INF" for positive infinity and upper- case "NINF" for negative infinity. If the curve is never concave upward, type an upper-case "N" in the answer field. t-interval: