(1 point) Given the curve R(t) - 2ti + 3t-j - 3+3 k (1) Find R (t) = 6jt-9t^2k+2i (2) Find R." (t) - -18kt+6j (3) Find the curvature k(1 point) Find the z coordinate of the point of maximum curvature (call it co ) on the curve y = 2e and find the maximum curvature, k(Zo) K(IO) =(1 point) Find the velocity v(t) and speed ||v(t) | of a particle whose motion is described by I = 212 - 20t + 50, y - 8t - 60tz, z = 4 v(t) =