Recent content by speedycatz

I get like U_n = cos(n \pi x) and \lambda _n = -(n \pi)^2 Is that correct?

Homework Statement Find U(x,t) dU/dt = d2U/dx2 + sin x Boundary Conditions: dU/dx (0,t) = 0 and U(1,t) = 0 Initial Condition: U(x,0) = cos 7*π*x 2. The attempt at a solution I start off with: d2(Un)/dx2 = λnUn (as an initial value problem) [d(Un)/dx](0) = 0...