Among the variations on the graphs of the trigonometric functions are shifts--both horizontal and vertical. Such shifts are easily accounted for in the formula of a given function. Take function f, where f (x) = sin(x) .
The running costs vary from gas to electric. The average running cost for an electric water heater is $550. The average running costs of a gas water heater is $400. The difference in usage price per year is $150.
An 50-gallon, 5,500-watt water heater with a .90 EF and an electricity rate of $.16 per kilowatt hour will cost $781 to operate each year. Most water heaters include a label listing the annual operating cost.