price elasticity of demand

if price fall from 10 to 9
along that demand increases from 100 to 110
%change is demand is 10%
%change in price is 10%

then ped = 1

but if we calculate revenue 10 x 100 = 1000
after price change revenue 9 x 110 = 990

so my question is even if price elasticity of demand is 1 we will not decide to decrease cost, organisation should check the revenue change before deciding.
Am i right sir?