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.
The cost of electricity is about 14p/kWh, which means that it would cost about 45p to run a 3kW immersion heater for an hour. Normally though the immersion will turn on and off via the thermostat so the amount of time they are on fluctuates, depending on the existing temperature of the water in the hot water tank.