Define f:[-2,2]---->R by

, x belongs to irrationals.

otherwise.

Suppose P is a partition of [1,2].

i) Show that L(f,P)=0

f has infimum zero in any subinteral. Therefore L(f,P)=0 for any partition P.

ii) How do i show

do we just say f has supremum greater than 1 in any subinterval. Therefore for any partion P.

iii) does exist?

Thank for any help.