given that S=( 0,1), show that the max S doesnt exist.

to show that, my notes states that:

let M ∈ S and M= max S.

take M* = (M+1)/2

then we need to show that M* ∈ S and that M < M*...

mayb i know if there is a fixed method that i can adopt whener i have to solve proving questions?