ex dr. du = .cos x и .du 1/di du sin dz = ㅎ Hence = cos r. cos & u. cost = ㅎ and do 8 being the flight path, it's independent upon. hance flight path is eyclaid.. flight-path cos(4) = 8 Sin du cost utan r For 4 r(t-sint). ' Ⓡ αξ 4 case = ucos dn dł do = d и созд = dn cas u sin r Ӣ using = u² ban'} cost u. The general solution. for for dr dn. 19 = u² tand » dn = u² tax & do. integrating both sides). n = u² sec² + C₂ where C. & C₂ are integral constants.. For ६ = У = (1-cast) y=h0-710=π+28 (ha-n) [(π+28) -sin (π +28)] hon = r. [1-cos (π +28)] hon = r. c.1+. cos 28) n. = ho n r. (It cas 28) = ho - E (I+ cos 28) I.207 Sơn 20 It Cos 28 A non-dimensional model of a glider flying to minimise flight-time in the absence of lift and drag is COSY = u' = - sin " и ε = u cosy, n = usiny § where is the flight-path angle, u is the non-dimensional velocity, & is the non-dimensional range, and 7 is the non-dimensional altitude and ' (prime) denotes differentiation with respect to 7, the non-dimensional time. The glider travels from § = 0, ŋ = h0 to $ = L,n = h₁, where ho > h₁ > 0, and, at the start of the motion, the glider is pointing vertically downwards so that 7=-π/2.