7.4达朗贝尔公式(4)

数学物理方法课件

例

2u0 ( x) = 2u0 0

x x1 , x2 x1 x x1 , x2 x1

x1 ≤ x ≤

x1 + x2 ≤ x ≤ x2 2 x < x1 , or , x > x2

x1 + x2 2

ψ ( x) = 0u ( x, t )

1 ( x) 2

(x)

u0

x1

x2x

u0x

x x

x1

x1 + x2 2

x2

1 u ( x, t ) = [ ( x + at ) + ( x at )] 2