Explain the relationship between Price Elasticity of Demand and Total Expenditure

Relationship between Price Elasticity of Demand and Total Expenditure is stated in following points:
(i) If Total Expenditure remains unchanged with increase or decrease in price, then it is unitary .
(ii) If direction of change in Total Expenditure is opposite to the direction of change in price, i.e. with rise in price, TE falls and vice-versa, then it is greater than unitary elastic demand.
(iii) If direction of change .in Total Expenditure is the same as the direction of change in price, i.e. with rise in price, TE rises and vice-versa, then it is less than unitary elastic demand.