dydx=dydtdxdt=4cos4t−sint ddt(dydx)dtdx=d2ydx2
ddt(−4cos4tsint)1−sint=d2ydx2
+4(−4sin4tsint−cos4tcost)(sin2t)1sint=y2
4(−4sin4t−cos4tsintcost)=sin2ty2 −16sin4t+costy1=sin2ty2 −16y=(1−x2)y2−xy1