For each of the following differential equations write down the differential operator L that would enable the equation to be expressed as L[x(t)] = 0:

dx (a) = f(t)x dt (b) (c) (e) 60 dx dt (h) dx dt (d) (sin t)- + (sin t)- dx d.x + (sin t) = (t + cost)x dt dt d.x bx dt t d ,d.x 1. dt dt dx dt dt t dt cost t = (f) + 4tx = 0 d d (tx)) -X d.x dt d -(xt) dt = = xt xte