Question

Given the sets A={1,6} and B={6,3,2,4,8}, compute

1) {x∈B.x is even}?

Answer 1

what have you got so far? BTW this is a Mathematics question.

Answer 2

its database question not maths

Answer 3

i think x = {2,6,4,8}

Answer 4

It's a database question only insofar as relational databases are based on set theory, which belongs to Mathematics. There is no computer science, let alone database, content in the question, even though it may very well have been asked in a database course.

Someone in a 3d graphics course may very well be asked how to rotate, translate and scale a vector, but if that's all he is asked to do, it's a Linear Algebra question, i. e., Mathematics.

And woleraymond is obviously correct (although it is slightly unusual not to put the set elements in ascending order).

Answer 5

The x∈B part says "let x be an element of the set B"
So {x∈B.x is even} means find all of the elements in set B that are even.
To find the set of answers, look at each element and ask yourself if it is even.
Is 6 even? If so, put it in your set of answers. Is 3 even? Is 2 even? ...

I also think woleraymond is correct. But I don't like his notation. The x was used to constrain the answer set. The answer should just be the set: {2, 4, 6, 8}