Question

The surface of a ball of radius A is kept at a temperature zero. If the initial temperature in the
ball is f (r), write down the boundary conditions and show that the temperature in the ball at
time t, u (r, t), is the solution to the equation:
c^2[(d^2u/dr^2)+2/r(du/dr)]=du/dt
note: here every du/dr or du/dt stands for partial differentiation wrt respected term

Answer 1

what kind of math is this,