5. Consider the following parametrization y(t) of the circle of radius r > 0 y(t) = (rcos(2nt), r sin(2nt)) = (x(t), y(t)), where t varies from 0 to 1. The curvature k(y) of y is defined to be * (7 ) = [xy" - y'z'l (1/2 + 4/2 ) 3/2 ' where r' = dx/ dt, x" = d'x/ dt?, y' = dy/dt, y" = d'y/dt2. Compute k(7)