2. Let f : R - R be defined by 4.r, TEQ f(x) = x2 +4, IEnQ Use the sequential criterion to show that f is discontinuous at 1 and continuous at 2.# Dugtion 8- 2 The given funchon is fo R - R flu ) = 2 2 + 4 End Q = rational numbers no = otherthan rational\fBy using sequential Criterion we get if fiD -R they noED iff an ED such that f (mm ) - f ( 210 )Let 2 = 1 here 1 END = 12+4 = 5 kim fing = Nim fias = 4 2 = A LHL = RHL * fu Hence function is discontinuary at