To Analysis the Relationship between the Demand Price Elasticity and Revenue

On the demand price elasticity and revenue, the traditional economics analysis result is that when E > 1, price and revenue reverse change; E <; 1, price and revenue are changing direction, Unit demand price elasticity, revenue is not with price changes ;But this conclusion is conditional. Through the proof: Unit price elasticity, any changes will reduce returns; When E <; 1, if prices don´t exceed 1 / E, the total income increase. E > 1,when prices drop as the range does not exceed 1 / E,total revenue increases.