Consider the below wave equation with the given conditions:
0 < x < 7, t > 0
u(0, t) = u(7, t) = 0, t > 0
The initial condition is:
u(x, 0) = 4x(7 - x) = ∑ (784/(̀^3 n^3)) {1 - (-1)^n} sin(ǹx/7), 0 < x < 7, n = 1, 2, 3, ...
The solution to the above boundary-value problem is of the form:
u(x, t) = ∑[n=1 to ∑] g(n, t) sin(ǹx/7)
Find the function g(n, t).