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A201905 Decimal expansion of the least x satisfying x^2+4x+2=e^x. 4

%I #6 Mar 30 2012 18:58:03

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

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

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

%N Decimal expansion of the least x satisfying x^2+4x+2=e^x.

%C See A201741 for a guide to related sequences. The Mathematica program includes a graph.

%e least: -3.425667410202877373265626064725816697827357...

%e nearest to 0: -0.35687491913863648565066705875991244...

%e greatest: 3.2349232177760663670327961327304430448478...

%t a = 1; b = 4; c = 2;

%t f[x_] := a*x^2 + b*x + c; g[x_] := E^x

%t Plot[{f[x], g[x]}, {x, -4, 3.3}, {AxesOrigin -> {0, 0}}]

%t r = x /. FindRoot[f[x] == g[x], {x, -3.5, -3.4}, WorkingPrecision -> 110]

%t RealDigits[r] (* A201905 *)

%t r = x /. FindRoot[f[x] == g[x], {x, -.36, -.35}, WorkingPrecision -> 110]

%t RealDigits[r] (* A201906 *)

%t r = x /. FindRoot[f[x] == g[x], {x, 3.2, 3.3}, WorkingPrecision -> 110]

%t RealDigits[r] (* A201907 *)

%Y Cf. A201741.

%K nonn,cons

%O 1,1

%A _Clark Kimberling_, Dec 06 2011

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Last modified April 24 20:08 EDT 2024. Contains 371963 sequences. (Running on oeis4.)