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11 let of be a bounded twice differentiable funchi on ( eval valued ) on R J . f " ( 2 ) 20 20 Then show that of is const. 1) let f. [ a, b] - R be twice differentiable and assume flaj= f(b)zo and of" ( n) cobx in (asb ) . Show that3 ) Consider the set consisting of all. cauchy sequences andnEN with an EN Un Is the set is countable ? let of be a mathise space . If A, BEX are disjoint, if Al's compact and if B is closed , then ? boo ! a - Bl 2 8 6 2 6 A BE B