Recent content by Gavran

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    Insights AI Enriched Problem Solving

    I remember the thread posted by @chwala in 2024, which is used as a reference in the article. The geometric solution provided by artificial intelligence is also described in the article. In this case, we cannot use it for comparing human labor with artificial intelligence labor because nobody...
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    High School Potato paradox

    A veridical paradox is one of three types of paradoxes, which is what defines it as a paradox.
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    High School Potato paradox

    100 kg of potatoes consists of 99% water. After some water evaporates, the potatoes consist of 98% water. What is the new weight of the potatoes? The answer is 50 kg. The explanation is simple. 100 kg of potatoes consists of 99% water and 1% dry matter, so the weight of the dry matter is 1 kg...
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    Solve the quadratic equation involving sum and product

    This can also be shown in the following way. ## \begin{align} &\arctan\frac\alpha c+\arctan\alpha=\arctan c\nonumber\\ &-\arctan\frac{\alpha}{\alpha\beta}+\arctan\alpha=\arctan c\nonumber\\ &-\arctan\frac1\beta+\arctan\alpha=\arctan c\nonumber\\ &\arctan\alpha-(\frac\pi2-\arctan\beta)=\arctan...
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    High School Three Squares Problem

    The equation ## C=A+B ## is actually Euler's formula $$ \arctan\frac12+\arctan\frac13=\frac\pi4 $$, and there are three more formulas of this kind. Hermann's formula $$ 2\arctan\frac12-\arctan\frac17=\frac\pi4 $$ , Hutton's or Vega's formula $$ 2\arctan\frac13+\arctan\frac17=\frac\pi4 $$ , and...
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    Prove that ## 4\tan^{-1}\left[\dfrac{1}{5}\right]- \tan^{-1}\left[\dfrac{1}{239}\right]= \dfrac{π}{4}##

    There are four formulas of this kind. Euler's formula $$ \arctan\frac12+\arctan\frac13=\frac\pi4 $$ Hermann's formula $$ 2\arctan\frac12-\arctan\frac17=\frac\pi4 $$ Hutton's or Vega's formula $$ 2\arctan\frac13+\arctan\frac17=\frac\pi4 $$ Machin's formula $$...
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    High School Three Squares Problem

    Based on the previous posts, it can also be shown that A+B+C=D for the angles A, B, C, and D in the next picture. Or A+B+C+D=E for the angles A, B, C, D, and E in the next picture.
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    Which material will stop magnetic attraction?

    I think you are right, and the correct answer is d. A copper shield can be better than a steel shield against a high-frequency magnetic field, but based on the picture from the original post, there is only a static magnetic field.
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    Graduate Expected numbers of cards of a last color remaining

    ## P(X=g) ## - probability that we have g green cards remaining ## P(X=b) ## - probability that we have b blue cards remaining ## P(X=r) ## - probability that we have r red cards remaining ## E ## - expected number of cards remaining $$...
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    Undergrad The vector to which a dual vector corresponds

    The author (A Student's Guide to Vectors and Tensors, by Daniel Fleisch, Cambridge, 2012., Chapters 4.5 and 4.6) does not mention a dual vector space. He does not speak in the context of a vector space and its dual vector space. He speaks in the context of the same vector space with two...
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    Geometric Game: Fun With Matches (Safe!)

    Agree with the above. “Find x where x2=4” versus “Find x where x2=4 and x>0"; two different problems with two different sets of solutions. Or post #28 versus post #31 ; also, two different problems with two different sets of solutions.
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    Geometric Game: Fun With Matches (Safe!)

    One more solution with three congruent equilateral triangles.
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    Is this the correct general solution of the given PDE?

    https://en.wikipedia.org/wiki/Linear_differential_equation#Homogeneous_equation_with_constant_coefficients...