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  2. Bretschneider's formula - Wikipedia

    en.wikipedia.org/wiki/Bretschneider's_formula

    Bretschneider's formula generalizes Brahmagupta's formula for the area of a cyclic quadrilateral, which in turn generalizes Heron's formula for the area of a triangle.. The trigonometric adjustment in Bretschneider's formula for non-cyclicality of the quadrilateral can be rewritten non-trigonometrically in terms of the sides and the diagonals e and f to give [2] [3]

  3. Perger prism - Wikipedia

    en.wikipedia.org/wiki/Perger_prism

    A Perger prism or Perger–Porro prism system is a prism, that is used to invert (rotate by 180°) an image. The special feature of this prism is that, like a traditional double Porro prism system, it manages this with only four beam deflections and has neither a roof edge with the accompanying phase correction problems, a mirrored surface or ...

  4. Bonferroni correction - Wikipedia

    en.wikipedia.org/wiki/Bonferroni_correction

    With respect to FWER control, the Bonferroni correction can be conservative if there are a large number of tests and/or the test statistics are positively correlated. [ 9 ] Multiple-testing corrections, including the Bonferroni procedure, increase the probability of Type II errors when null hypotheses are false, i.e., they reduce statistical ...

  5. Achromatic lens - Wikipedia

    en.wikipedia.org/wiki/Achromatic_lens

    Several different types of achromat have been devised. They differ in the shape of the included lens elements as well as in the optical properties of their glass (most notably in their optical dispersion or Abbe number).

  6. Euler's formula - Wikipedia

    en.wikipedia.org/wiki/Euler's_formula

    Euler's formula is ubiquitous in mathematics, physics, chemistry, and engineering. The physicist Richard Feynman called the equation "our jewel" and "the most remarkable formula in mathematics". [2] When x = π, Euler's formula may be rewritten as e iπ + 1 = 0 or e iπ = −1, which is known as Euler's identity.

  7. Dove prism - Wikipedia

    en.wikipedia.org/wiki/Dove_prism

    A Dove prism is a type of reflective prism which is used to invert an image. Dove prisms are shaped from a truncated right-angle prism. The Dove prism is named for its inventor, Heinrich Wilhelm Dove. Although the shape of this prism is similar to the shape described by a Dovetail joint, the etymology of the two is unrelated.

  8. Spearman–Brown prediction formula - Wikipedia

    en.wikipedia.org/wiki/Spearman–Brown_prediction...

    The Spearman–Brown prediction formula, also known as the Spearman–Brown prophecy formula, is a formula relating psychometric reliability to test length and used by psychometricians to predict the reliability of a test after changing the test length. [1] The method was published independently by Spearman (1910) and Brown (1910). [2] [3]

  9. Bessel's correction - Wikipedia

    en.wikipedia.org/wiki/Bessel's_correction

    Since the square root introduces bias, the terminology "uncorrected" and "corrected" is preferred for the standard deviation estimators: s n is the uncorrected sample standard deviation (i.e., without Bessel's correction) s is the corrected sample standard deviation (i.e., with Bessel's correction), which is less biased, but still biased