පයිප්ප සාදන්නා

imhotep

Well-known member
  • Mar 29, 2017
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    Please prove area of a circle using integrals, differentials, and other advanced formulas

    There should be many isn't it?
    The simplest proof - without any of the above is below.
    The area of any regular polygon is (a*p)/2 where a is the apothem (the line drawn from the centre of the polygon, perpendicular to any of the sides) and p is the perimeter.
    In the case of the circle a becomes the radius r snd p becomes 2(pi)r. Therefore the area is (pi)(r squared).

    Also there's a simple, just a couple of steps proof using the line integral for the area inclosed of a simple, closed and smooth curve, use the polar form for the curve as r cos(theta), r sin(theta), for theta to 0 to 2(pi)

    The more famous or popular one is the Onion Proof.
     

    upulpdn

    Well-known member
  • Mar 13, 2009
    34,672
    2,251
    113
    Kurunegala
    There should be many isn't it?
    The simplest proof - without any of the above is below.
    The area of any regular polygon is (a*p)/2 where a is the apothem (the line drawn from the centre of the polygon, perpendicular to any of the sides) and p is the perimeter.
    In the case of the circle a becomes the radius r snd p becomes 2(pi)r. Therefore the area is (pi)(r squared).

    Also there's a simple, just a couple of steps proof using the line integral for the area inclosed of a simple, closed and smooth curve, use the polar form for the curve as r cos(theta), r sin(theta), for theta to 0 to 2(pi)

    The more famous or popular one is the Onion Proof.

    There are Many methods. But there is a condition.
    With integral, differential and advanced formulas

    WITHOUT-
    GEOMETRY,
    " PI" (Because pi prooved using circle )

    Anyway, I'm not completely against you. I just love discussion :yes::cool:
     

    imhotep

    Well-known member
  • Mar 29, 2017
    14,858
    8
    35,447
    113
    There are Many methods. But there is a condition.
    With integral, differential and advanced formulas

    WITHOUT-
    GEOMETRY,
    " PI" (Because pi prooved using circle )

    Anyway, I'm not completely against you. I just love discussion :yes::cool:

    That would be difficult...with integrals yes. with added differential (??). advanced methods yes, possibly using Gaussian curvatures with integrals - there is But to have them together in one (????)
    Thanks.. I love mathematical problems too. - at least you get your brain into gear - rather than !@#$ politics.
     

    upulpdn

    Well-known member
  • Mar 13, 2009
    34,672
    2,251
    113
    Kurunegala
    That would be difficult...with integrals yes. with added differential (??). advanced methods yes, possibly using Gaussian curvatures with integrals - there is But to have them together in one (????)
    Thanks.. I love mathematical problems too. - at least you get your brain into gear - rather than !@#$ politics.

    Im Covering all topics except "asahana thread" :D
    Very less people attracting to post in mathematic threads now.
    Will see