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A195495
Decimal expansion of shortest length, (A), of segment from side AB through centroid to side AC in right triangle ABC with sidelengths (a,b,c)=(r-1,r,sqrt(3)), where r=(1+sqrt(5))/2 (the golden ratio).
5
4, 0, 5, 1, 7, 7, 8, 2, 9, 7, 2, 0, 5, 7, 1, 7, 7, 7, 8, 8, 0, 3, 0, 7, 3, 9, 4, 9, 8, 0, 5, 1, 4, 5, 8, 4, 6, 8, 8, 3, 2, 3, 9, 3, 7, 4, 0, 8, 9, 2, 3, 7, 6, 9, 9, 0, 7, 8, 5, 6, 5, 8, 0, 7, 3, 8, 9, 5, 8, 9, 0, 4, 6, 6, 4, 6, 2, 1, 3, 2, 6, 2, 2, 8, 4, 4, 7, 6, 8, 9, 3, 7, 6, 0, 2, 9, 7, 1, 8, 5
OFFSET
0,1
COMMENTS
See A195304 for definitions and a general discussion.
EXAMPLE
(A)=0.40517782972057177788030739498051458468832393740...
MATHEMATICA
a = b - 1; b = GoldenRatio; h = 2 a/3; k = b/3;
f[t_] := (t - a)^2 + ((t - a)^2) ((a*k - b*t)/(a*h - a*t))^2
s = NSolve[D[f[t], t] == 0, t, 150]
f1 = (f[t])^(1/2) /. Part[s, 4]
RealDigits[%, 10, 100] (* (A) A195495 *)
f[t_] := (t - a)^2 + ((t - a)^2) (k/(h - t))^2
s = NSolve[D[f[t], t] == 0, t, 150]
f2 = (f[t])^(1/2) /. Part[s, 4]
RealDigits[%, 10, 100] (* (B) A195496 *)
f[t_] := (b*t/a)^2 + ((b*t/a)^2) ((a*h - a*t)/(b*t - a*k))^2
s = NSolve[D[f[t], t] == 0, t, 150]
f3 = (f[t])^(1/2) /. Part[s, 1]
RealDigits[%, 10, 100] (* (C) A195497 *)
c = Sqrt[a^2 + b^2]; (f1 + f2 + f3)/(a + b + c)
RealDigits[%, 10, 100] (* Philo(ABC, G) A195498 *)
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Clark Kimberling, Sep 19 2011
STATUS
approved