# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a201755 Showing 1-1 of 1 %I A201755 #5 Mar 30 2012 18:58:02 %S A201755 1,9,6,4,6,3,5,5,9,7,4,8,8,8,6,4,5,0,7,6,2,2,6,5,9,6,9,2,1,1,0,9,7,7, %T A201755 5,8,8,3,7,5,3,0,7,5,0,6,3,7,9,4,2,2,8,1,1,5,2,1,9,7,9,5,8,3,2,3,5,7, %U A201755 0,1,6,4,3,2,2,0,8,8,1,3,2,7,7,9,0,4,8,2,1,7,3,5,1,7,0,4,8,3,0 %N A201755 Decimal expansion of the least x satisfying -x^2+4=e^x. %C A201755 See A201741 for a guide to related sequences. The Mathematica program includes a graph. %e A201755 least: -1.96463559748886450762265969211097... %e A201755 greatest: 1.058006401090636308621387446123... %t A201755 a = -1; b = 0; c = 4; %t A201755 f[x_] := a*x^2 + b*x + c; g[x_] := E^x %t A201755 Plot[{f[x], g[x]}, {x, -3, 2}, {AxesOrigin -> {0, 0}}] %t A201755 r = x /. FindRoot[f[x] == g[x], {x, -2.0, -1.9}, WorkingPrecision -> 110] %t A201755 RealDigits[r] (* A201755 *) %t A201755 r = x /. FindRoot[f[x] == g[x], {x, 1.0, 1.1}, WorkingPrecision -> 110] %t A201755 RealDigits[r] (* A201756 *) %Y A201755 Cf. A201741. %K A201755 nonn,cons %O A201755 1,2 %A A201755 _Clark Kimberling_, Dec 05 2011 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE