Hello,

I don't know that here is right forum for my question.

I want to solve this Heat Equation (Solution by Fourier series)

du/dt=d(2)u/dx^2 + e^(-t) 0<x<pi

du(0,t)/dx=du(pi,t)/dx=0

u(x,0)=cos(x)

I want to solve this differential equation.

Just I know I should use

u(x,t)=v(x,t)+w(x,t)

But how to find w(x,t) ? and more????