y=var('y')
y=function('y',x)
dy=diff(y,x,4)-16*y == 0
desolve_laplace(dy,y,x)
sol:

1/16*(4*D[0](y)(0) - D[0, 0, 0](y)(0))*sin(2*x) + 1/8*(4*y(0) - D[0,
0](y)(0))*cos(2*x) + 1/32*(8*y(0) - 4*D[0](y)(0) + 2*D[0, 0](y)(0) -
D[0, 0, 0](y)(0))*e^(-2*x) + 1/32*(8*y(0) + 4*D[0](y)(0) + 2*D[0,
0](y)(0) + D[0, 0, 0](y)(0))*e^(2*x)

1/16*(4*D[0](y)(0) - D[0, 0, 0](y)(0))*sin(2*x) + 1/8*(4*y(0) - D[0, 0](y)(0))*cos(2*x) + 1/32*(8*y(0) - 4*D[0](y)(0) + 2*D[0, 0](y)(0) - D[0, 0, 0](y)(0))*e^(-2*x) + 1/32*(8*y(0) + 4*D[0](y)(0) + 2*D[0, 0](y)(0) + D[0, 0, 0](y)(0))*e^(2*x)

Kreyszig-2.14_1 (last edited 2010-12-18 10:55:14 by santosh)