(35S) Perimeter of ellipse (Ramanujan 2nd Approximation)

[mchris]

Put the two radii in X and Y stack and execute. It uses registers A and B

Code:

P001    LBL P
P002    STO B
P003    RDN
P004    STO A
P005    RCL–B
P006    x^2
P007    RCL A
P008    RCL+B
P009    x^2
P010    /
P011    3
P012    *
P013    ENTER
P014    ENTER
P015    4
P016    X<>Y
P017    –
P018    SQRT
P019    10
P020    +
P021    /
P022    1
P023    +
P024    RCL A
P025    RCL+B
P026    *
P027    π
P028    *
P029    RTN