Word Problem about electricity function

Question

An electricity company charges its customers a base rate of $10 a month, plus 6 cents per kilowatt-hour(kWh) for the first 1200kWh and 7 cents per kWh for all usage over 1200 kWh. Express the monthly cost E as a function of the amount x of electricity used. 

Answer 1

Hi Alex,

        E(x)=10+.06x for 0<x<1200 kWH

        E(x)=82+.07x for x>1200 KWH

This makes E(x) a piecewise continuous function of usage 

 

Jim