Answer
Total revenue would remain the same/unchanged.
Work Step by Step
Since demand is that of unit elasticity, a change in price would result in a proportionate change in quantity demanded. Thus, regardless if price decreases or increases, total revenue would remained unchanged as in the case of a price decrease, a decrease in price would be met with a proportionate change in quantity, and therefore the area of (P x Q) gained would be equal to the area lost.
