Prove: If a is an irrational number, then the function y = cos (ax) + cos x is not periodic.
Is it possible to graphically represent or calculate this fact using an example?

If a point is chosen in the Euclidean plane, then it is red or black.
It must be proven that there is then an equilateral triangle with corners of the same color.

An oddly shaped Christmas package is a collection of centrally stacked cube-shaped boxes with ever smaller sides. From bottom to top, the edge lengths of the stacked cubes run like the sequence of the reciprocals of the sequence of the square roots of the natural numbers. How high is the package? How much paper is needed to wrap the package? What is the total volume enclosed by all the packages?

A farmer has exactly 100m of wire mesh fence available to enclose a pasture. The fence must begin and end at his large oak tree. To do this, imagine the usual "north-south/west-east" cross of the cardinal directions in the drawing plane. The oak tree is at the center of this.

1. All land that lies west of the imaginary axis is not worth a cent.

2. All land that lies east of the oak tree becomes continuously more expensive the further it is from the north-south axis. The property value is based on the function y = k · x, where y represents the price per square meter and x represents the distance in meters to the north-south axis. k is a proportionality factor, which for the task is k = 1 euro/m^3.

a) On which curve must the fence run so that the enclosed pasture area has the greatest possible value?

b) On which curve must the fence run if instead of the distance x from the north-south axis the distance r from the oak tree is decisive with the same factor k?

What we are looking for is a flat polygon with N corners and side lengths 1,..., N, which has a maximum surface area.
BTW:
1.) I am a Maple newbie and would like to get to know the diversity and power of the Maple world. For this reason, I occasionally post tasks here from various areas of mathematics and of varying difficulty levels in order to learn from the answers. Of course, I know the solutions to these tasks. So these are not homework.
2.) I have difficulty subsequently inserting text at any point in working worksheets. I keep getting error messages because "or" or ";" is missing. What am I doing wrong?