A $200 investment in a savings account grows according to A(t) = 200e^0.0398t, for t ≥ 0, where t is measured in years.

a. Find the balance of the account after 10 years.

b. How fast is the account growing (in dollars>year) at t = 10?

c. Use your answers to parts (a) and (b) to write the equation of the line tangent to the curve A = 200e^0.0398t at the point (10, A(10)).