Please help with practice problem 3 and 4.

3.

Let ci (t) = esti + 3 sin(t)j + t k and c2(t) = e-8ti + 5 cos(t)j - 7t'k. (Enter your solution as a single vector using the vector form (*,*,*). Use symbolic notation and fractions where needed.) dt [CI(t) + c2 (1 ) ] =Let em) = e4'i + 8 sin(t)j + t3k and c2(t) = e-4'i + 2 cos(t)j 10:3k. Determine the components of the result, a, b, and c, where d ED\" (t) x c2(r)l = (as b: C) (Express numbers in exact form. Use symbolic notation and fractions where needed. NOTE: this problem is computationally challenging.)