Homework Statement
Define a dimensionless radial coordinate as
x\,=\,r\,\sqrt{\frac{2\,h}{b\,k}}
and introduce y\,=\,T\,-\,T_a, and thus show the elementary equation
x^2\,\frac{d^2y}{dx}\,+\,x\,\frac{dy}{dx}\,-\,x^2\,y\,=\,0
describes the physical situation.
It gives the "physical...