Book
Advanced Engineering Mathematics
Author
Erwin Kreyszig
Edition
8th Edition
x=var('x')#2
y=function('y',x)
DE=diff(y,x,x)+9*y-sec(3*x)
desolve(DE,[y,x])
Solution by:
<Manjusha S. Joshi>, <Lecturee>, <Bhasakracharya Institute of Mathematics, Pune>