||'''Book'''|| Advanced Engineering Mathematics || ||'''Author'''|| Erwin Kreyszig || ||'''Edition'''|| 8th Edition || /* code_begins */ {{{ reset() x = var('x') y = function('y',x) # define y a function of x DE = x*diff(y,x) - x - y print 'DE:';show(DE) u = function('u',x) DE = DE.subs({y:x*u,diff(y,x):diff(x*u,x)}) # substituting y/x as u soln = desolve(DE,u) soln = soln.simplify_full() print 'Solution:';show(soln) }}} /* code_ends */ * '''Solution by''': * , , * , ,