Find two non-negative numbers whose sum is 9 and so that the product of one number and the square of the other number is a maximum

Find 2 positive numbers whose sum is 50 and have the largest possible product

Differentiate y=2x Sin x + 2 Cos x - x²

Two poles,one 6 meters tall and one 15 meters tall are 20 meters apart. A lenght of wave is aattached to the top of each pole and it is also stated to the ground somewhere between the two poles. Where should the wire be stated so that the minimum amount of wire is used?

A 2 feet piece of wire is cut into two pieces and and one piece is bent into a square and the other bent into an equilateral triangle. Where should the wire cut so that the total area established by both in minimum and maximum?

Airplane tickets cost $200 if between 0 and 50 passengers on the plane. However, for each additional passenger over 50, the price per ticket is reduced $2 for all passenger. For example if there are 52 passengers, then the cost of ticket per passenger is $196. How many passenger will produce the maximum revenue?

Find 2 positive numbers whose sum is 50 and have the largest possible product.