試題詳解

8. (5%) A string is stretched and secured on the x-axis at x = 0 and x = 1 for t＞ 0, that is initially held at these points 0.01sin(3tx) and then simultaneously reicased at all points at time t = 0. The string is released from rest from the initial displacement. (Wave equation constant: a)u(x,t) = 0.01f(x)g(t)
(A) g(t)=cos(πat),
(B) f(x)=sin(3πx),
(C) f(x)=sin(3παx),
(D) g(t) = cos(3πat),
(E) g(t) = sin(3πat).