[VA] Short & Sweet Math Challenge #22: April 1st, 2018 Spring Special

[Paul Dale]

Desert 3.

F(X) = X + 10⁹⁰.
G(X) = X - 10⁹⁰.

G(F(X)) is zero for |x| < 20. It's correct only at X=0. The smallest X where the difference is > 2% will be the largest negative number allowed in the small range around zero i.e. -19.999...999. The smallest in absolute will be the smallest positive X such that X - X/50 doesn't underflow.