Return the maximum positive and minimum negative product
if ( lowest < 0 and highest > = 0 ) return { max ( highPos , lowNeg ) , min ( highNeg , lowPos ) } ; else if ( lowest <= 0 and highest <= 0 ) return { lowNeg , lowPos } ; else if ( lowest >= 0 and highest >= 0 ) return { max ( lowPos , highPos ) , min ( lowNeg , highNeg ) } ; }