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A195475 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)=(1,sqrt(3),2) and angles 30,60,90. 1

%I #5 Mar 30 2012 18:57:45

%S 6,4,3,8,4,6,3,1,3,2,9,8,7,4,3,5,3,1,5,6,9,3,7,2,1,0,7,2,1,1,8,0,9,7,

%T 2,0,6,7,5,1,9,8,1,6,0,8,2,1,8,5,8,7,2,8,7,9,9,8,8,4,7,9,2,4,7,7,6,0,

%U 4,9,3,3,7,6,7,7,9,9,8,3,9,1,9,0,0,8,7,9,2,8,3,1,3,7,8,0,4,6,5,7

%N 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)=(1,sqrt(3),2) and angles 30,60,90.

%C See A195304 for definitions and a general discussion.

%e (A)=0.643846313298743531569372107211809720...

%t a = 1; b = Sqrt[3]; h = 2 a/3; k = b/3;

%t f[t_] := (t - a)^2 + ((t - a)^2) ((a*k - b*t)/(a*h - a*t))^2

%t s = NSolve[D[f[t], t] == 0, t, 150]

%t f1 = (f[t])^(1/2) /. Part[s, 4]

%t RealDigits[%, 10, 100] (* (A) A195575 *)

%t f[t_] := (t - a)^2 + ((t - a)^2) (k/(h - t))^2

%t s = NSolve[D[f[t], t] == 0, t, 150]

%t f2 = (f[t])^(1/2) /. Part[s, 4]

%t RealDigits[%, 10, 100] (* (B) A195576 *)

%t f[t_] := (b*t/a)^2 + ((b*t/a)^2) ((a*h - a*t)/(b*t - a*k))^2

%t s = NSolve[D[f[t], t] == 0, t, 150]

%t f3 = (f[t])^(1/2) /. Part[s, 4]

%t RealDigits[%, 10, 100] (* (C) A195577 *)

%t c = Sqrt[a^2 + b^2]; (f1 + f2 + f3)/(a + b + c)

%t RealDigits[%, 10, 100] (* Philo(ABC,G) A195578 *)

%Y Cf. A195304, A195476, A195477, A195478.

%K nonn,cons

%O 0,1

%A _Clark Kimberling_, Sep 19 2011

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Last modified April 24 07:54 EDT 2024. Contains 371922 sequences. (Running on oeis4.)