A198611 - OEIS

%I #11 Aug 01 2021 11:41:22

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

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

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

%N Decimal expansion of -x, where x < 0 satisfies 2*x^2+4*x = sin(x).

%C See A198414 for a guide to related sequences. The Mathematica program includes a graph.

%e -1.71054521091808440187340377301440319765795101...

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

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

%t Plot[{f[x], g[x]}, {x, -2, 1}]

%t r = x /. FindRoot[f[x] == g[x], {x, -1.72, -1.71}, WorkingPrecision -> 110]

%t RealDigits[r] (* A198611 *)

%Y Cf. A198414.

%K nonn,cons

%O 1,2

%A _Clark Kimberling_, Oct 27 2011

%E a(83) onwards corrected by _Georg Fischer_, Aug 01 2021