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WikiCards · Card list · Science cards · Cartesian product
Uncommon card · Science
Cartesian product, an Uncommon card
In mathematics, specifically set theory, the Cartesian product of two sets A and B, denoted A × B, is the set of all ordered pairs where a is an element of A and b is an element of B. In terms of set-builder notation, that is A × B = { ∣ a ∈ A and b ∈ B }.
- Rarity
- Uncommon
- Domain
- Science
- ATK
- 68
- DEF
- 62
- Power
- 130
- Wikipedia reads a year
- 120,000
Power 130 (ATK + DEF): stronger than 70 % of WikiCards cards.
Cartesian product quiz: 3 questions
Three questions on the Cartesian product card, the way WikiCards duels ask them. Pick an answer, the facts are just below.
Find the missing word
An ______ pair is a 2-tuple or couple.
Answer
ordered. An ordered pair is a 2-tuple or couple. From the Cartesian product article on Wikipedia.
Which of these cards hits hardest (highest ATK)?
Answer
Noether's theorem. Noether's theorem 81 · Inner product space 78 · Irrational number 73 · Cartesian product 68 ATK in WikiCards.
Which of these Wikipedia articles is read the most in a year?
Answer
Inner product space. Inner product space 200,000 · Irrational number 160,000 · Cartesian product 120,000 · Armour 79,000 Wikipedia reads over a year.
In a duel, each round asks a question like these about the opposing card, with 15 seconds to answer.
The facts on the card
The card carries these facts from its Wikipedia article.
- If the Cartesian product rows × columns is taken, the cells of the table contain ordered pairs of the form.
- One can similarly define the Cartesian product of n sets, also known as an n-fold Cartesian product, which can be represented by an n-dimensional array, where each element is an n-tuple.
- An ordered pair is a 2-tuple or couple.
Why it is Uncommon
Rarity in WikiCards follows a year of Wikipedia page views: the most read articles become Epic and Legendary cards. The Cartesian product article was read about 120,000 times in a year. ATK comes from the length of the article and DEF from its quality, so this card hits with 68 and blocks with 62: each hit it takes is cut by 25 %.
How to get Cartesian product
Open packs. Each pack holds five cards drawn from real Wikipedia articles, the rarest last, and the fifth card is always Rare or better. The odds are shown in the game. A free pack arrives every hour and two can wait, and the Coins you win in duels buy more packs.
More Science cards
Cards close in power
The cards just above and just below Cartesian product in the power ranking, all domains together.
- Arecibo ObservatoryUncommon · Science · ATK 71 DEF 59
- DioceseUncommon · Society · ATK 69 DEF 61
- CoahuilaUncommon · History · ATK 69 DEF 61
- Koch snowflakeUncommon · Nature · ATK 67 DEF 63
- MoraineUncommon · Nature · ATK 64 DEF 66
- BarberUncommon · Society · ATK 70 DEF 60
Card lists
- Wikipedia quizNew questions every day
- All cards from A to ZEvery card, by name
- Science cards
- Legendary cards
- Tier listS and A tiers by power (ATK + DEF)
Credits
Text : Wikipedia, Cartesian product (revision), CC BY-SA 4.0. Photo : Quartl, CC BY-SA 3.0, Wikimedia Commons.
