Quadratic formula, a Rare card

The card carries these facts from its Wikipedia article.

• Other ways of solving quadratic equations, such as completing the square, yield the same solutions.
• Given a general quadratic equation of the form ⁠ a x 2 + b x + c = 0 ⁠, with ⁠ x ⁠ representing an unknown, and coefficients ⁠ a ⁠, ⁠ b ⁠, and ⁠ c ⁠ representing known real or complex numbers with ⁠ a ≠ 0 ⁠, the values of ⁠ x ⁠ satisfying the equation, called the roots or zeros, can be found using the quadratic formula, x = − b ± b 2 − 4 a c 2 a, where the plus–minus symbol "⁠ ± ⁠" indicates that…
• Written separately, these are: x 1 = − b + b 2 − 4 a c 2 a, x 2 = − b − b 2 − 4 a c 2 a. The quantity ⁠ Δ = b 2 − 4 a c ⁠ is known as the discriminant of the quadratic equation.

Rarity in WikiCards follows a year of Wikipedia page views: the most read articles become Epic and Legendary cards. The Quadratic formula article was read about 350,000 times in a year. ATK comes from the length of the article and DEF from its quality, so this card hits with 72 and blocks with 56: each hit it takes is cut by 22 %.

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The cards just above and just below Quadratic formula in the power ranking, all domains together.