MeryLin4096 MeryLin4096 27-05-2023 Mathematics contestada Check by differentiation that y 2 cos 3 + 3 sin 3t is a solution to +9y-0 by finding the terms in the sum: y" -18 cos 31-27 sin 31 18 cos 31+27 sin 31 9y So y +9y=0