Request regarding desolve

kill(all)$             assume(%omega > 0)$
eq : 'diff(x(t), t, 2) + sin( x(t) ) = 0;
atvalue(diff(x(t), t, 1  ), t = 0, 0)$
atvalue( x(t), t = 0,  1)$
sol : desolve(eq, x(t));

yields these results


(%o2) 'diff(x(t),t,2)+sin(x(t))=0
(%o5) x(t)=ilt((g34028-laplace(sin(x(t)),t,g34028))/g34028^2,g34028,t)


Please advise regarding the interpretation & use of %o5. In particular, what is g34028?

Thank you,

Wilson Mixon