数学物理方法课件
习题 7.4.1 解：1 1 u ( x, t ) = [ ( x + at ) + ( x at )] + a ∫ ' (ξ )dξ 2 2a x at 1 1 = [ ( x + at ) + ( x at )] + [ ( x + at ) ( x at )] = ( x + at ) 2 2x + at
习题 7.4.6
2 2 2 ( 2 a )u ( x , t ) = 0 t x 2
(0 < x < ∞ )
设初始条件为 边界条件
u t = 0 = ( x)
和
ux
t =0
= ψ ( x)
ux
x =0
=
A sin ωt YS