For a long, thin insulated rod, a parabolic equation can be employed to characterize time -variable problems for a heat conduction equation in one dimensional which requires approximation for the

second derivative in space and the first derivative in time. а.In the calculation of heat conduction equation, describe the assumption that need to be considered. b.For one dimensional heat equation in insulated thin rod, derive equations for the first, internal and the last point of the grid. d.Select thebest method from the TWO (2) numerical methods in Part (2)(c). Justify your answer.