We want to find the increase in temperature of nitrogen gas at 1200 K when the specific

Question:

We want to find the increase in temperature of nitrogen gas at 1200 K when the specific internal energy is increased with 40 kJ/kg.
a) Find it from a constant Cvo from table A.5
b) Find it from a Cvo evaluated from equation in A.6 at 1200 K.
c) Find it from the values of u listed in table A.8