3. Suppose that the positions of two particles called Chenyan and John at the time t are given by the parametric curves: r1(t) = 2 cos(t) sin2(t)i + sin(t)j r2(t) = sin(t)i + cos(t)j (a) Express the set X = {t E R : y1(t) = y2(t)} in abbreviated form. Your answer to WebWorK Problem 30 should be useful. Note that X is innite. (b) Use your answer to (a) to nd the set C of tvalues for which there are collisions between the particles. (c) Find the two places in R2 at which the collisions you found in (3.) occur