(12C Platinum) Length of An Ellipse

[Albert Chan]

(07-07-2019 05:44 AM)Gamo Wrote:  Program: RPN mode: "Program run this formula in three terms" ...

You might consider Ramanujan's approximation, less code and almost 2 extra terms!

Replace steps 011-031 with this:

Quote:011 Enter
012 x ; h = ((a-b)/(a+b))^2
013 3
014 x
015 Enter
016 Enter
017 4
018 -
019 CHS
020 SQRT
021 1
022 0
023 +
024 /
025 1
026 + ; correction = 1 + 3h / (10 + sqrt(4-3h))

Using your example, a=50, b=10, FIX 5, we get ellipse perimeter = 210.10028, absolute error = -0.00017