Raymond B. answered 01/09/21
Math, microeconomics or criminal justice
one counterexample disproves a proposition
if a > -1 then 1/a < -1 is false if a > 0 such as +2>-1 but +1/2 is not < -1
that leaves only the interval -1<a<0 such as a = -1/2 then 1/(-1/2) = -2<-1
if a>-2 then 1/a <-1 is true only if -1<a<0
it's true only if a is a negative proper fraction, with denominator greater than the numerator
such as -1/3, -3/4, - 15/16.
for "if a>-1 then 1/a <-1" is true only if a is in the interval open (-1,0)