Consider two diffuse surfaces A1=0.1m2 and A2=0.1m2 on the inside of a spherical enclosure of radius R=1.2m. Using the following methods derive an expression for the view factor F12 in terms of A2 and R. (a) Find Fi2 by beginning with the expression Fij=AiJiqij. (b) Find Fi2 using the view factor integral, Fij=Ai1AiAjR2cos(i)cos(j)dAidAj