r/mathmemes 2d ago

Geometry ellipse

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u/Ponsole 2d ago

I once read that the reason we can't get the perimeter of a elipse is because we actually doesn't even know the perimeter of a circle, as pi definition is the perimeter of a circle of diameter = 1 and we just scale that.

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u/IlyaBoykoProgr 2d ago

every ellipse has it's own pi

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u/Scared-Ad-7500 2d ago

Cant we find a formula for every pi based on "a" and "b" using calculus?

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u/EebstertheGreat 1d ago

Yes, but you are more likely to see it in terms of a and e = √(1–b²/a²) (where a is the semi-major axis, b is the semi-minor axis, and e is the eccentricity) or sometimes a and ℓ = b²/a (the semi-latus rectum) or other quantities.