What are duties of the national chairman?

campaign manager and fund-raiser
campaign fund spending and fund management
public relationships
assisting the president in awarding loyal party workers
all of the above

From the given, duties of the national chairman are

Explanation:

Chairman of the political party national committee who usually serves as part of the permanent organization of the party and has overall control of the political party policy in particular during elections

One of the decisions made by the President after the elections is the role of a regional President.

President Trump's selection for national chairperson is Ronna McDaniel of Michigan.

One of the Chairman's important duties is to guarantee that the organisation's management is competent. The national president is the one who overlooks a national committee's activities and management.

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