Let s ⊆ r be nonempty. prove that if a number u in r has the properties: (i) for every n ∈ n the number u − 1/n is not an upper bound of s, and (ii) for every number n ∈ n the number u + 1/n is an upper bound of s, then u = sup s.

addition

step-by-step explanation:

what is the answer to this

the height of the surface increases from the center out to the sides of the road.

step-by-step explanation:

as we move out we move away from the x-axis.

and as mentioned in the problem statement that height of a road increases when we move away from the center x.

hence proved that 3rd option

the height of the surface increases from the center out to the sides of the road.

is the correct option.