Calculate e:
  e =? 1.0
  e =? 2.0
  e =? 2.5
  e =? 2.6666666666666665
  e =? 2.708333333333333
  e =? 2.7166666666666663
  e =? 2.7180555555555554
  e =? 2.7182539682539684
  e =? 2.71827876984127
  e =? 2.7182815255731922
  e =? 2.7182818011463845

Calculate sqrt(1000):
  sqrt(1000) =? 500.5
  sqrt(1000) =? 251.249000999001
  sqrt(1000) =? 127.61455816345908
  sqrt(1000) =? 67.72532736082603
  sqrt(1000) =? 41.24542607499115
  sqrt(1000) =? 32.745269344488634
  sqrt(1000) =? 31.642015868650788
  sqrt(1000) =? 31.622782450701045
  sqrt(1000) =? 31.622776601684336
  sqrt(1000) =? 31.622776601683793
  sqrt(1000) =? 31.622776601683793

x = 1.0E15, x+1 = 1.000000000000001E15, x-1 = 9.99999999999999E14
x = 1.0E16, x+1 = 1.0E16, x-1 = 1.0E16

x = 1.0E-15, 1+x = 1.000000000000001, 1-x = 0.999999999999999
x = 1.0E-16, 1+x = 1.0, 1-x = 0.9999999999999999

x = 1.0E154, x*x = 1.0E308
x = 1.0E155, x*x = Infinity

x = 1.0E-161, x*x = 1.0E-322
x = 1.0E-162, x*x = 0.0

Solving x*x/1000 - 1000x + 1/1000 = 0
  (-b+sqrt(bb-4ac))/(2a) = 999999.999999
  (-b-sqrt(bb-4ac))/(2a) = 9.999894245993346E-7
  (2c)/(-b+sqrt(bb-4ac)) = 1.000000000001E-6