A particle moves along the plane trajectory y (x) with velocity v whose modulus is constant. Find the acceleration of the particle at the point x = 0 and the curvature radius of the trajectory at that point if the trajectory has the form (a) Of a parabola y = ax2;
(b) Of an ellipse (x/a)2 + (y/b)2 = 1; α and b are constants here.