The given statement is true. If n^2 is even, then n is even.

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Nov 11
The proof that 0.999... = 1 is elementary, using just the mathematical tools of comparison and addition of (finite) decimal numbers.

86

Nov 11
The Euler's formula states that for any convex polyhedron, the number of vertices and faces together is exactly two more than the number of edges. This can be proven using the Noah's Ark method, which states that if you have a convex polyhedron with V vertices, E edges, and F faces, then V - E + F = 2.

101

Nov 11
This excerpt proves the Pythagoras' Theorem using Euclid's proof.

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Nov 11
The Pythagorean Theorem states that the length of the diagonal of a square is equal to the square root of 2. This proof shows that the square root of 2 is irrational.

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Nov 11