Upside Down U In Math Probability

The symbol is an upside down u like this.

Upside down u in math probability. The set made by combining the elements of two sets. If an element is in just one set it is not part of the intersection. If two sets are being combined this is called the union of the sets and is indicated by a large u type character. I wikipedia d the symbol but the explanations weren t really clear.

So the union of sets a and b is the set of elements in a or b or both. Not sure if both these symbols relate in any way. If instead of taking everything from the two sets you re only taking what is common to the two this is called the intersection of the sets and is indicated with an upside down u type character. The intersection of the soccer and tennis sets is just casey and drew only casey and drew are in both sets which can be written.

The symbol is a special u like this. I think i looked for the wrong symbol also because i know there is also the really big u symbol that is right side up of the letter u.