determine whether the following functions are injective, surjective, and bijective. provide brief justifications for your answer. if a function is not bijective, modify either the domain or the co-domain (but not both) to make the function bijective. 1. f : [−π 2 , π 2 ] →[0, 1], x 7→cos x. 2. f : r →r, x 7→ex