3-18. A flat plate in an ambient at temperature T[infinity] receives from a source the net radiant heat flux q"(Fig. 3-52). The thickness of the plate δ is much less than its length 2L; the third dimension of the plate extends to infinity. The upward and downward heat transfer coefficients are h1, h2, respectively. The heat transfer coefficient from the ends of the plate, if needed, may be taken to be h3≠h1≠h2. Find the temperature distribution in the system