Compute ddt fcrarrt using the chain rule compute ddt

Question

Let f(x, y) = x² + y and let c^→(t) = (e^t, e^-t).

a. Compute (d/dt) f(c^→(t)) using the Chain Rule.

b. Compute (d/dt) f(c^→(t)) without using the Chain Rule, but instead first writing the composition f(c^→(t)) as a function of t, then differentiating with respect to t in the usual Calc I way.