4. let f r-z defined by f(x)= 5 |. show that f is not one-to-one by exhibiting a counterexample. 5 pts. counterexample: let y -2 the tt 2 such that 5 2 10 shows that 5 all evel intqeus renot to-one one note 1.2, 1. 3 er and 12/3 -5 you shad fat f2) = f(l3 c(t001'1331) let f: r-r defined by f(z) = x2 - 2. show that f is not onto by exhibiting a counterexample. [you cannot use the reason that the codomain the range]. note 5. 5 pts. counterexample: 36e r, he codma 2 bat fz)= x ryou shw fhat kr, dhe domain