Number 12.20 Please help me

where A is a 12.20. Suppose the coordinate transformations between the Cartesian coordinates and plane polar coor- dinates contain time explicitly given by x = r cos 6 + u and y = r sin 0 + at? . where v and a are constants. Show that the kinetic energy in plane polar coordinates is not a ho- mogencous quadratic function of the velocities r and 0: Find Lagrange's equations of motion.