Which of the following functions fi: R → R, i = 1,2,3 are injective? Which ones are surjective? Jusitfy your answer and evaluate fi[-1, 1] and f ¹-1,1]. (a) (b) (c) fi(x) = (x-1, if x ≥ 0 [x+1, if x < 0 f2(x)= {{# f3(x) = -x-1, if x ≥0 K [x², if x ≥ 0 12³, if a < 0