DSolve[-y[x]^3 - (y[x]^2*Derivative[1][f][x])/(2*f[x]) + (y[x] - (3*Derivative[1][f][x])/(2*f[x]))*Derivative[1][y][x] + y[x]*(f[x] + Derivative[1][f][x]^2/f[x]^2 - Derivative[2][f][x]/(2*f[x])) + Derivative[2][y][x] == 0,y[x],x]