тогда:
X'по t= (2sin^2 t+sin2 t)'= (2sin^2 t)'+(sin2 t)'= 4sin t*cos t+2cos2t= 2sin2t+2cos2t= 2(sin2t+cos2t)
(Y'по t)/(X'по t)= 1/((cos^2 t)(sin2t+cos2t))
так?