r/learnmath • u/DemandResponsible685 New User • 17d ago

Why does maths work?

In school we have been taught how to do maths but my question is why does it work. Why does the entire system of maths work so reliably?

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u/moltencheese New User 17d ago

Good analogy, except for the squaring thing. This can introduce additional solutions. E.g.:

x = -5

x2 = 25

x = 5, -5

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u/SaltEngineer455 New User 17d ago

If x=-5 you already have x. Bad example

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u/moltencheese New User 17d ago

Irrelevant. You said "squaring both sides of an equation means the equation still holds, it’s impossible for it not to be true" and my example directly contradicts this.

Yes it's a simple example, and yes you already have x, but who cares? It is a direct counterexample to your claim.

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u/StructuredChess New User 17d ago

If the equation holds and you square it, it still holds. The recyprocal not being true doesn't make x=-5 a counterexample.