For u_tt = 25 u_xx, what is the signal speed c?

• 25
• 5
• 625
• 1/5

For u_tt = u_xx with u(x,0) = 0 and u_t(x,0) = 1, use d'Alembert's formula to find u(5,3).

For u_tt equals u_xx with zero displacement and velocity 4 everywhere, use d'Alembert's formula to find u(3,2).

A triangular pulse starts on an infinite string with speed 1. After 3 seconds, each of the two travelling copies still has its sharp peak.

For u_tt equals u_xx with zero displacement and velocity g(s) equals 2s, what is u(1,1)?

• 4
• 2
• 0

For u_tt = 9 u_xx, one characteristic through (1,2) has the form x - 3t = const. What is that constant?

For u_tt = 9 u_xx, what is the domain of dependence of the point (0, 1)?

• [-1, 1]
• [-3, 3]
• [-9, 9]
• [0, 3]

For u_tt = u_xx with u(x,0) = x² and u_t(x,0) = 0, use d'Alembert's formula to find u(0,2).

For u_tt equals u_xx with displacement x squared and zero velocity, use d'Alembert's formula to find u(3,2).

For u_tt equals 4 u_xx, the domain of dependence of the point (0,t) has length 4t.