Write a Racket two-way selection structure that will produce a list '(1 2 3) when the first element of a list named a_lst is identical to the atom 'a and an empty list otherwise. Note that you are NOT required to write a function definition!

Octothorpe is another name for what common computer keyboard symbol?

Write a method that takes in an array of point2d objects, and then analyzes the dataset to find points that are close together. be sure to review the point2d api. in your method, if the distance between any pair of points is less than 10, display the distance and the (x,y)s of each point. for example, "the distance between (3,5) and (8,9) is 6.40312." the complete api for the point2d adt may be viewed at ~pf/sedgewick-wayne/algs4/documentation/point2d.html (links to an external site.)links to an external site.. try to write your program directly from the api - do not review the adt's source code.

Universal windows platform is designed for which windows 10 version?