“…The using of substitution y(o, t) z(o1, t)e1(1t and solving the obtained equation (10) C(t)±(,, 1) + (G(t) +jo,C(t))z(o1, t) + as((oi, t) = 0 (10) with respect to envelope cot, t) avoids this problem. The known integration techniques can be applied to solve (10).…”