Question

Problem 1.3. For each function fi, determine whether it is injective but not surjective, surjective but not injective, bijective, or neither injective nor surjective. Explain why. (1) f1: R20 + R with f1(x) = x2 for all x ER>, where R20 = {x ER|X>0} = [0, ). (2) f2: R20 + R20 with f2(x) = x2 for all c ER>0. (3) f3: R + Ryo with f3(2) = x4 for all x € R. (4) f4: R R with f4(:1) = 1022 for all 2 E R. (Here 1022 stands for 10(2), not (102)2.)

Answer 1

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