QUESTION NINE
(a) Given the function f(t) = 2t² - 3t + 4, find $$\frac{dy}{dt}$$ | $$_{t=3}$$ from the first principle.
[7]
(b) Find $$\frac{d^2y}{dx^2}$$ of the function y = (3x - 2x²)(5 + 4x).
[5]
(c) Evaluate the integral $$\int 3x^3 dx$$.
[3]
(d) Mr. Chimwemwe has a farm which uses bio energy for dairy machines operation. In the
Annual Energy Outlook, the farm Information administrator projected the consumption C
(in quadrillion of Btu per year) of petroleum to follow the model Cā = 0.004t² +
0.330t + 38.3, 0 ⤠t ⤠30 where t = 0 corresponding to 2000. If the actual
consumption more closely follows the model
Cā = 0.005t² + 0.301t + 38.2, 0 ⤠t ⤠30. How much petroleum would be saved? [5]