sine q # q l and the constant c1 cannot be equal to two different things at the same time, there is no solution in this case . this is not surprising since this case corresponds to supplying heat to the plane well from both sides and expecting the temperature of the wall to remain steady ( not to change with time ) . this is impossible.
(c) in this case, the same values for heat flux are specified at the two boundaries. the application of the boundary condition gives