Who presides over the senate when the president of the senate is not present?

The President pro tempore designates other senators to preside in his absence, generally new members of the majority party.  The Constitution provides for two officers to preside over the Senate.  The Vice President of the United States is designated as the president of the Senate.

local max is .5

step-by-step explanation:

the local maximum is for x values between 2 and 4

it looks like the x value is 2.5 and the y value is .5